[HN Gopher] Internal Combustion Engine
       ___________________________________________________________________
        
       Internal Combustion Engine
        
       Author : algui91
       Score  : 2019 points
       Date   : 2021-04-30 09:15 UTC (1 days ago)
        
 (HTM) web link (ciechanow.ski)
 (TXT) w3m dump (ciechanow.ski)
        
       | dandare wrote:
       | Why are the bearings filled with oil instead of being normal ball
       | bearings? All the other bearings in the whole car are ball
       | bearings.
        
       | thunderbong wrote:
       | This page is a work of art.
       | 
       | And going through the archives[0], looks like all the pages are!
       | 
       | It's really, really rare to see this level of care, attention and
       | detail put to something we all consider will be seen only for a
       | few seconds. But as a testament to the adage "the cream rises to
       | the top", I spent around an hour going through the website.
       | 
       | Pure craftsmanship. Thank you.
       | 
       | [0]: https://ciechanow.ski/archives/
        
       | mraza007 wrote:
       | Anyone who's interested in learning how the car engine works
       | 
       | This is worth watching
       | 
       | https://youtu.be/ZQvfHyfgBtA
        
       | engineer_22 wrote:
       | What a great website, awesome animations, and intuitive
       | interactives
        
       | umvi wrote:
       | How were these animations made? SolidWorks?
        
       | netfortius wrote:
       | My first masters was in mechanical engineering, in the field of
       | what ~40yrs ago was known as "Thermal Engines" (internal
       | combustion engines, turbines, etc.). I have long departed the
       | field (~90s), for CS (degree and work in the field, accordingly),
       | but this article felt truly like a lost love one remembers all
       | details about, with all good memories flooding the brain from way
       | back... thank you!!
        
       | knolan wrote:
       | I'm a lowly mechanical engineering lecturer. I use Jupyter
       | notebooks to teach fluid mechanics[0]. I make videos of fluid
       | flows with Blender and embed them with the notes along with some
       | basic Python code examples so that students are aware of how
       | basic code can make an Engineer's life easier (even if Matlab is
       | the standard platform).
       | 
       | I also embed simple 3D models with pyGEL3D[1]. It's fine but very
       | limited. I'm always blown away by this gentleman's work when it
       | comes up here on HN and would like to use JavaScript instead, but
       | I've no idea where to start. Can anyone recommend a good book or
       | online course that would put me on the right path?
       | 
       | [0]
       | https://nbviewer.jupyter.org/github/nolankucd/MEEN20010/tree...
       | 
       | [1] http://www2.imm.dtu.dk/projects/GEL/PyGEL/
        
         | axelerator wrote:
         | I recommend trying to get started with webGL Elm [0]. It's a
         | language that compiles to JS to run in the browser. It's a
         | functional language and saves you from having to deal with most
         | of the historical baggage of JS.
         | 
         | [0] https://lucamug.medium.com/3d-graphics-in-the-browser-
         | with-e...
        
         | vagrantJin wrote:
         | I'm on mobile so linking is a bit of a schlep.
         | 
         | 1. MDN is a good starting point to learn Javascript.
         | 
         | 2.Then the three.js library for 3D in the browser.
         | 
         | 3. Maybe P5.js as well for 2D.
        
         | helixc wrote:
         | Why do you have to learn JS? If you just want to make a web app
         | and add some interactive 3D models on it, there're some Python
         | libraries can help with that, like:
         | https://github.com/streamlit/streamlit
         | https://github.com/wang0618/PyWebIO
         | https://github.com/plotly/dash
        
           | knolan wrote:
           | Why learn JS? I guess it's because I think it'll be a useful
           | skill that will allow me to do more in the future, not just
           | find a better way to embed 3D models in a notebook.
           | 
           | It might be useful to build tools for research projects,
           | interactive elements for assessment etc.
           | 
           | The bulk of my coding is work Matlab and an increasing amount
           | of Python. JS would allow me to to more web based stuff.
        
         | kghvlgvkg wrote:
         | There's an array of javascript libraries to choose from, but
         | maybe you would find Observable (reactive javascript notebooks)
         | to be a good substitute for Jupyter.
         | 
         | Observable is geared toward the use of d3.js (essentially a
         | library for drawing charts and graphs) which can be a bit
         | intimidating, but you can use other libraries as well. For 3D,
         | regl seems to be a good option. It's a library which makes
         | using WebGL a bit more convenient. Here's an example of an
         | Observable notebook that uses regl:
         | https://observablehq.com/@rreusser/contour-plots-with-d3-reg...
         | 
         | Check out R. Reusser's other notebooks too. My guess is that
         | choosing a set of JS libraries/tools to learn is the hard part,
         | here, once you've committed to javascript.
         | 
         | http://regl.party/
        
           | knolan wrote:
           | Thanks, I'll take a look.
           | 
           | I use Jupyter because it's something that the students are
           | finding used more and more when they go on industrial
           | placement. Matlab is extremely popular in engineering but
           | Python is growing.
           | 
           | My notebooks are deliberately simple so it's not I
           | ntimidating for students who are frequently terrified by
           | code. The point is to show them that some basic readable code
           | can help them solve problems and avoid going too deep into
           | the weeds.
        
         | lasagna_coder wrote:
         | For the graphics: - https://webglfundamentals.org/ -
         | https://threejs.org/
         | 
         | For general JS: - https://developer.mozilla.org/en-
         | US/docs/Web/javascript#tuto...
         | 
         | There's other stuff like build tools, cross-browser, and other
         | stuff, but that's likely to be confusing and not super
         | necessary to begin with. The above should be enough to get you
         | running with what it sounds like you want to do.
         | 
         | I appreciate you sharing those links. I'm trying to learn
         | mechanical engineering stuff myself, if you have any further
         | useful learning materials I would love to see them.
        
           | knolan wrote:
           | Much appreciated. I'll be adding to the fluid mechanics
           | notebook this summer.
           | 
           | What areas are you interested in?
        
             | lasagna_coder wrote:
             | Mechatronics, which is why I'm interested in mechanical
             | engineering. I guess this mostly implies servomechanisms,
             | kinematics, motors.
        
         | lasagna_coder wrote:
         | Also I would trade you mech eng tutoring for JS tutoring, if
         | you've got the time.
        
           | techdragon wrote:
           | I wish there were more opportunities for people to learn via
           | "cross training" like this.
           | 
           | I'd love to learn more about a number of engineering
           | disciplines by helping people who know those fields, learn
           | how to implement the algorithms and mathematical calculations
           | they need in Python and simultaneously, learning more about
           | those algorithms and calculations in order to best implement
           | them and show how best to use Python for these tasks.
           | 
           | But unfortunately such opportunities are few and far between
           | outside academia and other learning oriented environments in
           | my experience.
        
             | knolan wrote:
             | I love this idea. The best way to get academics to buy in
             | would be to have some clear outcome such as a publication
             | or funding opportunity.
             | 
             | There are a lot of clunky engineering tools that would
             | benefit greatly from professional software development.
             | Computational Fluid Dynamics software in particular is just
             | plain awful in terms of usability for beginners.
        
               | lasagna_coder wrote:
               | What are the names of some of this software that are a
               | good example of in-use but are clunky/have awful
               | usability? I ask because it sounds like an interesting
               | area, and I would like to see for myself what you're
               | working with.
        
               | knolan wrote:
               | On one hand there is Ansys. It's a Frankenstein's monster
               | of a software suite for numerical simulation comprising
               | several tools that have been acquired over the years.
               | It's frightfully expensive and there's no incentive to
               | make it more usable as there's limited competition.
               | 
               | Then there's OpenFOAM which is a fantastic open source
               | alternative. It's entirely command line based but there
               | are UI derivatives and cloud based versions (SimScale).
               | However it's a nightmare of disjointed code, difficult to
               | build and heavy on dependencies. You spend all your time
               | dealing with endless problems related to defining simple
               | geometries in the basic BlockMesh tool and then dealing
               | with and compiling various solvers. It's a research grade
               | tool and not a polished piece of software. I won't go
               | into the various versions with incompatible differences.
               | 
               | Getting the most basic stuff working is tedious and
               | frustrating in both.
               | 
               | After a few years of this masochism you just get on with
               | it. However, when you are trying to guide students
               | through the software for their final year project they
               | spend about two thirds of their time just figuring out
               | how to get something simple running and then never want
               | to touch CFD ever again.
               | 
               | Then there's Blender where I can install it in seconds
               | and set up a simple flow simulation with a
               | straightforward workflow. Sure the result is not remotely
               | accurate but that's just the solver, there is no reason
               | for the complexity of the workflow in Ansys or OpenFOAM
               | other than it was designed by (Mechanical) Engineers who
               | know nothing about good software design.
        
               | lasagna_coder wrote:
               | Thanks for the info! Heh, if Blender is your only go to
               | alternative for ease of simulations and usability, then
               | there's definitely a need for improvement.
        
           | knolan wrote:
           | What's this time you speak of?
        
             | lasagna_coder wrote:
             | (new Date()).toLocaleString()
        
       | cratermoon wrote:
       | When I was a boy, my dad decided that our '66 Mustang with a
       | straight 4-cylinder engine needed new piston rings. I helped a
       | bit but mostly watched as he tore down the engine to the barest
       | elements, only the engine mounts keeping the block held up in the
       | compartment. The crankshaft, connecting rods, tappers valves,
       | piston heads, piston rods, all laid out neatly on the garage
       | floor along with all the nuts, bolts, washers, seals, gaskets,
       | belts, and everything else you see in this video.
       | 
       | Although I really appreciate the reliability, efficiency, and
       | durability that modern engine design has brought, a part of me is
       | sad that modern cars are all about chips and software, and the
       | average guy in his garage or under a shadetree can no longer
       | break one down to the bare bones of electromechanical parts and
       | put it back together better than it was.
        
         | cx4life wrote:
         | I think the design of a wiring harness is actually a good
         | analogy for a well-created API, in that it provides a handful
         | of endpoints, each of which fulfills a "contract". On modern
         | wiring harnesses, it's pretty hard to connect the wrong thing,
         | because the connectors are physically "typed", in that the male
         | and female sides are uniquely shaped so only they will mate up,
         | rather than having a generic connector that plugs in to every
         | sensor.
         | 
         | On the contrary, twisting a distributor to set timing, or doing
         | _anything_ on a carburator, will make you long for those
         | aspects of ICE to be abstracted to control by software. Weirdly
         | enough, that's what's happened over time in cars with direct
         | injection controlled by ECUs.
        
           | cratermoon wrote:
           | Obviously it's nostalgia for me, but timing lights,
           | distributors, points, carburetor ports and butterfly valves,
           | you could really see into the mechanisms. Hell, my dad (who
           | was a master mechanic and worked on cars and railroad diesel
           | engines to put himself through college) took a drill to the
           | fuel injectors on a shitty 80s Chrysler engine that was
           | knocking and stalling when cold (no amount of adjusting the
           | choke could fix it). I drove that POS in my college years and
           | never had a problem with it.
        
           | throwaway0a5e wrote:
           | If you're doing minimally invasive wrenching on stuff that is
           | in good condition electronics are fine until you have to do
           | serious work to them.
           | 
           | Grafting two engine harnesses together because you can't buy
           | the one you need (because nobody sells that stuff for 20+yo
           | vehicles) will make you want a carburetor.
        
         | pengaru wrote:
         | > Although I really appreciate the reliability, efficiency, and
         | durability that modern engine design has brought, a part of me
         | is sad that modern cars are all about chips and software, and
         | the average guy in his garage or under a shadetree can no
         | longer break one down to the bare bones of electromechanical
         | parts and put it back together better than it was.
         | 
         | That's a totally flawed understanding of modern ICE vehicles.
         | 
         | There was an era of vacuum-line misery separating the 70s and
         | 90s, where you'd almost certainly never get it back together
         | and functioning good as new again with the literal miles of
         | vacuum lines and solenoids.
         | 
         | But modern stuff, especially with just 4 cylinders, is
         | relatively simple and entirely DIY servicable. Wiring harnesses
         | have replaced all the vacuum lines, and everything has a
         | physically unique connector pair, and the harness routing is
         | well described in the service manual. So all the guesswork is
         | gone there, honestly the worst part on new stuff is not
         | overlooking any of the grounding lugs.
         | 
         | I share your attitude WRT modern EVs, but I bet if we just
         | treat the controller and battery as black boxes we don't
         | attempt to disassemble and service, the rest is just more of
         | the same simple machinery except with no hazardous gasoline and
         | motor oil to drain and handle.
        
           | buffet_overflow wrote:
           | An aspect that appeals to me is interchangeability. If you
           | needed to replace an engine or other major components, even
           | just to similar items in the manufacturers lineup, there's
           | definitely a "golden era" of late 80s to early 2000s cars
           | where that is feasible for the...more enthusiast home
           | mechanic. While not impossible for modern cars, it is far far
           | more difficult.
        
           | Reason077 wrote:
           | > _" Wiring harnesses have replaced all the vacuum lines"_
           | 
           | Of course, now days the wiring harnesses themselves have
           | become huge and unwieldy in many vehicles - literal miles of
           | cables! Automakers are looking at technologies like
           | automotive ethernet and even wireless communication in order
           | to reduce the cost, size and complexity of wiring.
           | 
           | > _" I share your attitude WRT modern EVs, but I bet if we
           | just treat the controller and battery as black boxes we don't
           | attempt to disassemble and service"_
           | 
           | Some EV batteries are quite serviceable (eg: LEAF), with the
           | pack being able to be disassembled right down to the cell
           | level relatively easily. Although admittedly, some modern
           | pack designs are moving away from this level of
           | serviceability (eg: Tesla, whose cells are cemented in place
           | with fire-retardant foam/glue. Disassembly is a one-way
           | operation).
           | 
           | Things like motor controllers/inverters tend to be very
           | reliable so there is rarely any need to disassemble or
           | service them during the lifetime of the vehicle. If they do
           | fail there's a ready supply of affordable replacement parts,
           | thanks to salvage from crashed vehicles, so it's often easier
           | to just replace a faulty part than attempt to service.
        
             | pengaru wrote:
             | > Of course, now days the wiring harnesses themselves have
             | become huge and unwieldy in many vehicles - literal miles
             | of cables!
             | 
             | Engine harnesses are not that bad in my experience,
             | especially not for a small 4-cyl. Chassis harnesses, with
             | all the bells and whistles they keep piling into
             | smartphones on wheels, agreed. But we're talking about
             | engines here.
             | 
             | > Things like motor controllers/inverters tend to be very
             | reliable so there is rarely any need to disassemble or
             | service them during the lifetime of the vehicle. If they do
             | fail there's a ready supply of affordable replacement
             | parts, thanks to salvage from crashed vehicles, so it's
             | often easier to just replace a faulty part than attempt to
             | service.
             | 
             | I figured as much. This is basically already the case with
             | all the various modules littering the chassis in modern ICE
             | vehicles. We don't service the power steering or engine
             | control modules; it either works or you replace it, usually
             | with some cheap used replacement from a wrecker. Unless the
             | car's been flooded, the miles and age don't seem to be a
             | problem except the occasional cold solder joint.
             | 
             | Many more of my hours have been wasted fussing with jets
             | and floats on old carburetors than any control modules on
             | these newfangled computerized vehicles.
        
         | hellbannedguy wrote:
         | Plus it doesn't help when vechicle manufacturers will not share
         | repair information with the customer, or independant repair
         | shops.
         | 
         | It doesn't help when they refuse to sell scanners to
         | independant shops, or customers.
         | 
         | Yes---vechicles are much more complicated, but every vechicle
         | sold in America should be required to tell customers up front
         | about the ease, and accessibility of required repair
         | information.
         | 
         | My point is if they didn't hide repair information we might not
         | look at modern vechicles as Challenger space ships.
         | 
         | I have been casually looking to buy a new vechicle, and every
         | salesperson laughed when I asked about buying a factory manual.
         | 
         | Sales guy, "Oh--no one works on their car anymore, they bring
         | it here." Sign behind him said, Shop rate is $275 hr. People
         | drinking Starbuck's coffee for free though.
         | 
         | My father told a salesman to throw in a factory service manual
         | on the sale of a '97 Dodge Dakota. Salesman, "Hell yes!". He
         | gave him the manual before he received the truck.
         | 
         | And yes--after dealing with a failed smog check this week, and
         | seeing the PID only shows up on the dealership scanner, I am
         | more than pissed over propiatiary information. Failed
         | smog--$125 gone. A trip to the dealership $450, for a sensor
         | that one of the better scanners didn't have access to.
         | 
         | I went to Automotive School, and worked on all my vechicles
         | ever since.
         | 
         | I am so hesitant on buying a new car.
         | 
         | Today is definitely my Right to Repair Day.
         | 
         | I thought about RTR movement while shopping. I was trying to
         | think about being out, people getting vaccinated, friday, but
         | that Right to Repair was stuck in my mind. We need to all get
         | behind the movement.
         | 
         | (To tired to edit.)
        
       | chmk wrote:
       | Impressive didactic gem here, this is what the web was created
       | for.
        
       | larsnystrom wrote:
       | In a few decades the internal combustion engine will be to
       | transportation what the typewriter is to typing today. It's kind
       | of mind boggling, but there is really no alternative if we want
       | to stop increasing the CO2 concentration in our atmosphere.
        
         | kirse wrote:
         | Pure EVs will reach a fundamental peak percentage similar to
         | any other car class... Hybrid powertrains are really where the
         | next 20-30 years are headed for the bulk of vehicles.
         | Automotive racing and supercars have demonstrated hybrids are
         | the most effective setup for the past decade, and barring some
         | major breakthrough in battery tech that will all trickle down
         | into consumer cars over the next 0-20 years.
        
           | Hypx_ wrote:
           | Hybrids are facing _real_ challengers from a combination of
           | PHEV, synfuel, hydrogen combustion and hydrogen fuel cell.
           | While it is the ideal car of today I wouldn 't be so sure
           | about the next 20-30 years.
        
           | slfnflctd wrote:
           | > Hybrid powertrains are really where the next 20-30 years
           | are headed for the bulk of vehicles
           | 
           | It depends what you mean by 'bulk'. I see a major future here
           | for big trucks-- right now, 99%+ of our long-haul tractor
           | trailer semis are pure ICE. There is no way to fully
           | electrify that fleet quickly, so I believe hybrid tech is
           | being seriously underestimated in this space (especially for
           | retrofitting).
           | 
           | I've been expecting to see this emerge for over 5 years, I'm
           | not sure what's taking so long. Likely it's a catch-22 of the
           | industry being resistant to change, while large chunks of
           | (reluctant) investor funded R&D are necessary to make it
           | viable. In any case, I think some larger scale tests are
           | finally being run this year, so I'm looking forward to the
           | results of that.
           | 
           | As far as consumer vehicles go, well... we should electrify
           | almost all of it. Simply the best choice for the majority of
           | use cases. But that's going to take a while, and will affect
           | battery availability, which is all the more reason why big
           | trucks will need a longer transition phase that hybrids are
           | perfect for.
        
           | londons_explore wrote:
           | As soon as governments get serious about CO2 emissions,
           | Hybrid powertrains will end up as a "worst of both worlds"
           | position.
           | 
           | Already across most of Europe all subsidies and discounts
           | that applied for "eco friendly cars" no longer apply to
           | Hybrids.
           | 
           | That leaves few people wanting to buy a hybrid - it won't be
           | cheapest _or_ most eco friendly.
        
             | tmh88j wrote:
             | Not sure I agree with that. I don't think you realize how
             | many cars have switched over to hybrid powertrains, but are
             | not advertised as a main selling point like the Prius or
             | Volt. Volvo's entire lineup is now hybrid or electric along
             | with their new performance brand Polestar. Mercedes is
             | switching over to hybrid powertrains even on their AMG
             | models. Audi's using hybrid powertrains even on their
             | highest performance models like the RS6 and their ultra
             | luxury vehicles like the A8. Hybrid technology is great for
             | sports cars and offers many advantages over fully electric,
             | most importantly being the weight savings.
        
               | snazz wrote:
               | It definitely feels like you get some free low end torque
               | in a hybrid as well.
        
             | jandrese wrote:
             | I think the thinking on hybrids will shift from "smaller
             | gas engine with an electric boost to help with merging on
             | the highway" to "range extension option for the electric
             | car." They'll be configured to not even fire up the gas
             | engine until the battery pack is run down enough.
        
         | Viker wrote:
         | Hmm... Hard to beat that energy density when the workload is
         | large.
         | 
         | Trucks, tractors, planes, ships. Sure consumer cars will be EV
         | but ICEs are not going anywhere
        
           | whatever1 wrote:
           | People have hard time grasping how much energy chemical bonds
           | can hold. 15 gallons of gasoline store 500kWh of energy. That
           | is 5 tesla model s worth of energy.
           | 
           | Efficiency plays role for our day to day car tasks, but when
           | you have to deal with external forces or higher requirements
           | of momentum, then you need more energy period. Towing,
           | beating high-speed drag / waves, climbing high, cannot be
           | addressed with smarter design. You need to be able to store
           | somehow enough energy to deal with these external forces /
           | additional required momentum
        
             | outworlder wrote:
             | > 15 gallons of gasoline store 500kWh of energy. That is 5
             | tesla model s worth of energy.
             | 
             | Yes. However, the Carnot efficiency means that most of it
             | is lost as heat. Suddenly the advantage is not that large
             | anymore.
        
               | whatever1 wrote:
               | Not even close. An electric motor is 4 times more
               | efficient than ice. An ice car can easily store 10 times
               | more energy than an electric.
               | 
               | F150 can tow 13,000 pounds and has a 27 gallon tank
               | (almost 10 Tesla's).
        
           | dahfizz wrote:
           | This sparked my curiosity...
           | 
           | Currently gasoline has about 50x more energy per unit weight
           | than a tesla battery pack.
           | 
           | Battery energy densities have tripled in the past 10 years.
           | Keeping on that pace, it would take over 30 years for
           | batteries to be competitive with gas.
           | 
           | When you account for the astoundingly bad efficiency of ICE,
           | though, the gap in usable energy decreases. This is why a
           | tesla can go 300+ miles with a battery that can only store
           | the same energy as 2.4 gallons of gas.
        
             | rsj_hn wrote:
             | The Tesla can go 300 miles by making it light, aerodynamic,
             | brakes that recharge the battery, not turning on the
             | heater, etc. Yes, it's a significant engineering
             | accomplishment, but in the heavy long haul world when
             | analyzing break-even points what matters is range
             | improvements due to an increasing energy/weight ratio, not
             | range improvements due to reducing air resistance and
             | inertia. This is because the form factors of the boxcar are
             | basically set by shipping container needs and the weight is
             | going to be determined by the load you are carrying. Munro
             | is advocating for hydrogen powered trucks and planes as
             | hydrogen has similar power/weight characteristics to gas --
             | electrification of these is going to be a challenge.
        
               | outworlder wrote:
               | > by making it light
               | 
               | If there's one thing that EVs are not, is "light". Model
               | S ranges from 4,561 to 4,941 lbs. A model 3, 3,648 to
               | 4,250 lbs. A Nissan Leaf - 3,538 to 3,946 lbs.
               | 
               | In comparison, a Honda Civic weights 2,771 to 3,012 lbs.
               | 
               | Regenerative breaking is nice but it's very dependent on
               | the particular drive and terrain. Heaters are power
               | hungry as there is very little waste heat that can be
               | used (again, due to the high efficiency), unless they are
               | heat pumps.
               | 
               | The main reason they can go so far with so little energy
               | is the efficiency of electric motors.
               | 
               | > as hydrogen has similar power/weight characteristics to
               | gas
               | 
               | No it doesn't! It has horrible energy density per volume,
               | compared to any gas or liquid fuels. You can improve this
               | by using high pressures (energy loss) or cryogenics (even
               | more energy loss). But it's pretty bad to begin with.
               | Turns out that the best way to store hydrogen is by
               | adding some carbon atoms to it.
        
               | rsj_hn wrote:
               | > If there's one thing that EVs are not, is "light".
               | _sigh_
               | 
               | Obviously we are not comparing about the weight of an EV
               | compared to an apple or vehicle that doesn't require a
               | battery. We are talking about extreme measures taken to
               | make the car lighter so it can improve range. Replacing
               | cheaper steel with more expensive aluminum, reducing even
               | surface area of plastics, reducing wires. Truly amazing
               | steps were taken to reduce weight.
               | 
               | > No it doesn't! It has horrible energy density per
               | volume,
               | 
               | volume? Seriously? "The energy in 2.2 pounds (1 kilogram)
               | of hydrogen gas is about the same as the energy in 1
               | gallon (6.2 pounds, 2.8 kilograms) of gasoline."
               | https://afdc.energy.gov/fuels/hydrogen_basics.html
        
               | twicetwice wrote:
               | You're comparing mass to volume in that last paragraph
               | there. Based on a quick google search, that 1 kilogram of
               | hydrogen is going to take up 3.4 gallons as a cryogenic
               | liquid--so even more as a compressed gas.
               | 
               | Source: http://www.uigi.com/h2_conv.html
        
             | Hypx_ wrote:
             | You're likely to hit a hard limit to what battery energy
             | density can reach. The next step will be fuel cells which
             | don't have the efficiency limits of traditional internal
             | combustion.
        
           | Hypx wrote:
           | ICEVs will outlast BEVs. Just like it did 100 years ago.
        
           | Hypx_ wrote:
           | ICEVs will outlast BEVs. Just like it did 100 years ago.
        
           | legulere wrote:
           | Don't forget to talk about rockets! Although there weight is
           | more important than volume.
        
             | jabl wrote:
             | Volume matters too, especially for lower stages. There's a
             | reason for the lack of success of hydrolox 1st stages.
        
         | rhinoceraptor wrote:
         | I wouldn't be so sure, I think there's a decent chance that
         | e-fuel can be made economically viable.
        
         | peter303 wrote:
         | Hydrogen works fine in ICEs with modest modifications.
         | 
         | Hydrogen can be created with nearly any energy source:
         | renewable, natural gas, etc.
         | 
         | There is a large infrastructure for moving fuels.
        
       | rlonn wrote:
       | This makes me appreciate even more the advantages electrical
       | motors have over ICEs.
       | 
       | If you build a naive version of an ICE, it will have lousy
       | performance, at best. It might not even operate without a lit of
       | mechanical tricks and tweaks. An electrical engine, however, can
       | be built simply and still get decent, if not great, performance.
       | 
       | The complexity of ICEs really is a huge disadvantage and there is
       | no turning back.
        
         | namelosw wrote:
         | Perfect example of "Simplicity is a great virtue but it
         | requires hard work to achieve it and education to appreciate
         | it." - Edsger W. Dijkstra
        
       | smusamashah wrote:
       | How can we preserve article like this forever?
        
         | lasagna_coder wrote:
         | Forever is a stretch, but, being the web, you can always save
         | the page and store it somewhere locally. It'll probably be
         | archived by the wayback machine soon anyway.
        
       | fractalb wrote:
       | What an excellent illustrative write-up. I don't even know what a
       | four-stroke engine is all these years! Thanks to the author, I do
       | know now :)
        
       | endisneigh wrote:
       | How were these animations made? They're excellent!
        
         | bob1029 wrote:
         | view-source:https://ciechanow.ski/js/ice.js
         | 
         | I find this to be a very impressive implementation.
        
           | wyuenho wrote:
           | I wonder if it's completely written by hand from scratch or
           | done with something like emscripten.
        
             | fuzzybear3965 wrote:
             | He said on Twitter that he hand-wrote the animation code.
        
         | fuzzybear3965 wrote:
         | He posted a bit of information on his Twitter:
         | 
         | https://twitter.com/BCiechanowski/status/1387827101294686210...
        
       | louwrentius wrote:
       | This is very nicely done, I love it.
        
       | joshuaengler wrote:
       | This guys writings are consistently some of the best in the
       | world. His web design mixed with the articulate easy to
       | understand vocabulary, and fantastic easy-to-understand motion
       | illustrations are absolutely the finest I've ever seen.
        
         | arduinomancer wrote:
         | Agreed. The graphics/animation are obviously great but even the
         | actual explanations/text are really clear and well written.
        
       | senbarryobama wrote:
       | Who did the 3D graphics for this post?
       | 
       | EDIT:
       | https://twitter.com/BCiechanowski/status/1387827101294686210
        
       | busymom0 wrote:
       | For those interested, the author has a lot of similarly excellent
       | explanations over the years:
       | 
       | https://ciechanow.ski/archives/
       | 
       | I am curious about the 5 years gap between 2014 and 2019.
        
       | bitwize wrote:
       | Reminds me of how I got into computing in the first place.
       | 
       | During the 1970s, my dad designed an engine, similar in principle
       | to the Wiseman Engine: https://wisemanengine.com
       | 
       | To better explore and elucidate his ideas, he bought a TRS-80
       | Model 16 computer (Model II compatible) with high resolution
       | graphics option and wrote a BASIC program that could compare the
       | mechanical advantage graphs of several different engine
       | mechanisms including his own. He had begun to add a visualization
       | of the mechanism itself to the program. He had only completed the
       | slider crank (what is used in most auto engines), but there it
       | was, animated at half a frame a second: a wireframe drawing of a
       | piston that moved up and down, pushing on a crank that turned the
       | crankshaft. And my brain was like what manner of high wizardry is
       | this!!
       | 
       | This site is exemplary of what I had glimpsed that day, going on
       | 40 years ago: the power computers have to explain our world and
       | bring alive the principles that drive it.
        
       | therein wrote:
       | I have always wondered, if it would be possible to make a small
       | enough internal combustion engine so that you could just have it
       | laying around in an apartment, sitting a few feet away from you,
       | powering your appliances or charging a 12V or 24V battery.
       | Dispensing the exhaust through a long tube. If all goes well,
       | complete combustion of propane should yield CO2 instead of CO
       | anyway. An additional enclosure shouldn't be an issue given the
       | generator is small enough anyway.
       | 
       | The smallest propane powered generator I can find is basically
       | still not much more silent or smaller than Honda EB2200.
       | 
       | Imagine a 350W generator that you can connect to a camping style
       | propane tank that you use to charge some batteries.
       | 
       | I played around with setting up such a system with a Sterling
       | engine but couldn't achieve high efficiency.
       | 
       | Surprised to see no YouTuber with the necessary machining skills
       | and CNC equipment attempted to build a mini internal combustion
       | engine / inverter generator.
        
         | baybal2 wrote:
         | Yes, first 40% efficient ICE was made almost a century ago, but
         | those were very big engines.
        
         | sbierwagen wrote:
         | >Micro combined heat and power is an extension of the idea of
         | cogeneration to the single/multi family home or small office
         | building in the range of up to 50 kW.[1] Usual technologies for
         | the production of heat and power in one common process are e.g.
         | internal combustion engines, micro gas turbines, stirling
         | engines or fuel cells.
         | 
         | https://en.wikipedia.org/wiki/Micro_combined_heat_and_power
         | 
         | Unfortunately, looks like the smallest CHP unit Dalkia Aegis
         | will sell you in the United States is the Yanmar CP35, which
         | does 204,040 BTU/h. https://aegischp.com/products/product-
         | comparison/
        
         | catmanjan wrote:
         | Washing machines and other appliances used to be powered by ICE
         | when the grid was not widespread
        
         | nemo44x wrote:
         | Wouldn't it be loud as hell? Even 4-stroke small engines are
         | inefficient all things considered.
        
         | blamazon wrote:
         | In japan some rural households use propane solid oxide fuel
         | cells in this manner. Instead of combusting the fuel, which is
         | loud, it's pushed through a piece of exotic ceramic which
         | causes a chemical reaction that splits the fuel into hydrogen
         | gas and water vapor--the resulting free electrons are used for
         | electricity, the hydrogen gas is used as a home/water heater
         | and to keep the ceramic fuel cell at its reaction temperature,
         | and the water vapor is simply vented.
        
         | chrisdalke wrote:
         | For sure miniature gensets exist! They're often used on gas RC
         | / autonomous airplanes to generate supplemental electricity.
         | Here's one: https://www.youtube.com/watch?v=1yB49G756OI
         | 
         | I think the answer is that the miniaturization reduces
         | efficiency, adds a ton of tiny, expensive parts/maintenance,
         | and doesn't generate a lot of power compared to what you can
         | store in a battery. So while the idea is cool, it's really only
         | applicable in a few specialized use-cases like long-duration
         | drone flight.
         | 
         | You've got to also compare it to other available power
         | generation schemes -- A single 250W solar panel is far cheaper,
         | simpler, and eco-friendly.
        
       | dysrend wrote:
       | I wish this guy would write a textbook on life. Someone throw
       | infinite capital at him.
        
       | alanbernstein wrote:
       | A few thoughts while reading this:
       | 
       | In addition to a deeper understanding of engine _manufacturing
       | considerations_ than I even knew I cared to learn, this article
       | helps me appreciate why people are into engine work.
       | 
       | The perfect tolerances and synchronization of these machines
       | makes me a little ashamed to use the word "engineer" in my title
       | of "software engineer". There is no real comparison of the
       | quality of the result.
       | 
       | And then I skimmed the source, and it makes me think the author
       | deserves that title. It also validates my belief in vanilla
       | javascript.
       | 
       | edit: And later it occurs to me that Mr. Ciechanowski is a true
       | craftsman of software; handmade and built to 1) Be beautiful (and
       | informative), 2) last for years. (The open web standards are the
       | ones that seem to stick around the longest, for better or for
       | worse. (I'm ignorant of the shader world though))
        
         | ehnto wrote:
         | I have had the same thought, software can often feel messy and
         | unpolished. But to be fair to ourselves, we simply don't
         | require the same tolerances in most software.
        
         | worewood wrote:
         | > makes me a little ashamed to use the word "engineer" in my
         | title of "software engineer". There is no real comparison of
         | the quality of the result.
         | 
         | I think that's because the barrier to entry is too low and
         | anybody is being called a "software engineer" these days.
         | 
         | But think about a system which makes proper use of
         | synchronization primitives, like an OS kernel or a robotic
         | control, or a CPU design like the other guy commented too, or
         | maybe a 3D game with tricks like that of John Carmack. Those
         | things can be as complex as an ICU engine.
         | 
         | To make an analogy: in the physical world there are the
         | engineers, and the mechanics.
         | 
         | In the software world everybody is a software engineer.
        
           | tjr225 wrote:
           | I kinda wish my title was simply "Systems Administrator"
           | which is probably the closest thing to a "software mechanic"
           | that we have. Most of our titles have been inflated however.
        
             | ehnto wrote:
             | Thank fuck fluff titles like "Happiness Engineer" have gone
             | away though.
        
           | zikzak wrote:
           | When I took "Software Engineering" in University, the prof
           | was very careful to explain in great detail, and frequently,
           | that the field was not mature enough to really be called
           | engineering. Then he would talk at length about things like
           | software for airplanes and spacecraft. It is impossible to
           | call yourself an engineer while looking someone in the eye
           | after taking his class. I am a software developer. Maybe an
           | analyst. But mostly a developer.
        
             | [deleted]
        
           | djmips wrote:
           | That's why I often joke that a big part of my work is as a
           | software mechanic! Which is still highly technical and
           | necessary but the engineering part happens less often.
        
           | toolslive wrote:
           | I _am_ a computer scientist, but also had a course "Gasoline
           | and Diesel engines" at university. (Belgium before Bologna)
        
           | kortilla wrote:
           | > Those things can be as complex as an ICU engine.
           | 
           | From a complexity perspective an ICU isn't nearly as complex
           | as even something as simple is a script scraping a webpages
           | for links and queuing them up for further crawling. I'm not
           | sure if "complex" is the word you are going for but even the
           | TCP state machine has significantly more complexity than an
           | ICU and that's just a fragment of what it takes to transmit
           | some data.
           | 
           | The composability and abstractions we have in this industry
           | allows you to quickly dwarf any regular mechanical system.
           | There is a reason this is a whole new era beyond the
           | industrial revolution.
        
             | foepys wrote:
             | I don't think you can compare both. It's abstractions all
             | the way down, for both. Modern ICE are made from metals
             | compounds that were unknown a few years ago and are the
             | reason they are efficient. Just as you can send bytes over
             | a wire without TCP, you can build an ICE from pure iron.
             | But both then have just very low fault tolerances and break
             | rather quickly.
        
             | themeiguoren wrote:
             | Well that's just because we understand internal combustion
             | engines well enough that we can abstract away a lot of the
             | details. Software engineering is nice because by design it
             | is at a level of abstraction that we can grok it. We're
             | basically manipulating structural concepts of pure thought.
             | But never forget that reality has a surprising amount of
             | detail. When we interact with the physical world, we rely
             | on abstractions at our peril.
             | 
             | http://johnsalvatier.org/blog/2017/reality-has-a-
             | surprising-...
        
             | d110af5ccf wrote:
             | Quantifying complexity really depends on the level of
             | abstraction though.
             | 
             | Scraping a static webpage is simple when examined at the
             | level of abstraction involving Python and ready made
             | packages. An ICE is similarly simple when examined from the
             | perspective of basic mechanics, as in the article under
             | discussion.
             | 
             | As you note, scraping that static webpage is no longer
             | simple when you include as part of your assessment the TCP
             | state machine, kernel interface, NIC firmware, and similar
             | layers that had previously been abstracted away. Neither is
             | the ICE though once metallurgy, machining, oil chemistry,
             | and the physics of combustion are included.
             | 
             | Granted, pursued to the logical extreme software eventually
             | drags in everything the ICE did and more due to the
             | physical hardware. But then modern engines are controlled
             | by computers ...
        
               | mauvehaus wrote:
               | The complexity in the engine isn't in the mechanical
               | concepts that make it tick, it's in the implementation
               | details. Stepping back quite some time in technology, but
               | staying with engines:
               | 
               | The platonic carburetor is a dead simple device: a
               | Venturi, a jet, and a butterfly valve. Real life
               | carburetors are fiendishly complex: multiple jets, an
               | accelerator pump, a choke. And god help you if you have
               | multiple carbs on a single engine and need to sync them.
               | 
               | Everything that goes into making an engine work is
               | similar: cooling it correctly and evenly, allowing for
               | operation while parts expand and contract at different
               | rates as the engine reaches operating temperature,
               | lubricating everything, preventing vibrations that'll
               | make the car feel unrefined or maybe tear the engine
               | apart, valve timing (fixed in most engines at some
               | compromise between performance and drivability), ignition
               | timing (variable in most engines), sealing things that
               | need to be sealed across a huge range of operating
               | temperatures and in the presence of differing rates of
               | thermal expansion (head gaskets, among others) oh, and
               | making it work for a quarter million miles or more with
               | fairly minimal maintenance. And manufacturing them at
               | enormous scale, and holding the tolerances that make all
               | of the above possible across the lifespan of the
               | production line.
               | 
               | And all of _that_ is before we even discuss pollution
               | controls.
        
         | H8crilA wrote:
         | Excuse me, but modern CPUs are way more complicated than this,
         | even if you only look at "arranging events in time". Like
         | several orders of magnitude more complicated. Anyone who has
         | touched VHDL/Verilog knows how delicate signal propagation is,
         | and how crafty you have to be with the clock.
         | 
         | And even if you never tinkered with transistors surely you've
         | at least looked at assembly code, and the amount of
         | painstakingly detailed data layout orchestration that is going
         | on there. A simple printf("hello world") is magical if you know
         | what happens under the hood.
        
           | cblconfederate wrote:
           | Most people who write software do not know/care how circuits
           | work, as they shouldn't. Car engineers similarly don't need
           | to know how bridges are built.
        
           | 1cvmask wrote:
           | I doubt most of the readers here on HN ever wrote anything in
           | assembly. It is like comical interaction of Marc Andreesen
           | and Mark Zuckerberg and how Zuckerberg had no idea on the
           | Netscape browser (let alone Mosaic or Gophers).
           | 
           | https://www.businessinsider.com/when-mark-zuckerberg-met-
           | mar...
           | 
           | https://en.wikipedia.org/wiki/Gopher_(protocol)
        
           | Valakas wrote:
           | It's easy to dismiss the difficulty of something when all you
           | see is a webpage explaining things very well and simply with
           | some cool graphics. That webpage looks really cool, but this
           | is just a front page of the result. The backend of all the
           | math, equations and thoughts involved wouldn't be so visually
           | appealing. This is just the pretty part result. If you would
           | delve into the actual math and physics that was required for
           | this I'm pretty sure you'd reconsider that statement. Just
           | the study of vibrations alone is probably as difficulty as
           | whatever you're talking about. And that's just one of several
           | areas of study that needs to be considered when making a
           | machine like this. Then you need static mechanics, dynamic
           | mechanics, thermodynamics, fluid mechanics, knowledge of
           | manufacturing processes, materials, among others. And each of
           | these topics is HUGE in itself. You probably have no idea
           | because you're a software engineer? It's easy to defend our
           | own realm and dismiss others, when we know little about
           | others' or all we know is based on some cool animations we
           | saw on the web once.
        
           | alanbernstein wrote:
           | Well, Electrical and Computer Engineering is an extremely
           | precise discipline, and while the line between hardware and
           | software can be fuzzy in many cases, web software is an
           | entirely different world from VLSI design, and even from
           | instruction set design. And of course, some software, at all
           | abstraction levels, is extremely well engineered as well. But
           | it doesn't seem to be the norm.
           | 
           | Most importantly, I'm talking about my own ability more than
           | the best in the field.
        
           | jason0597 wrote:
           | The vast majority of people on this site have never written a
           | line of C or Assembly in the past 12 months
        
         | porknubbins wrote:
         | Achievements in other disciplines can often look like magic
         | (and some are but it usually takes experts to tell which). I
         | think fundamentally engines are engineered like software- by
         | solving one problem at a time. And after having gotten a
         | distributed consensus algorithm to work with a perfect dance of
         | elections and voting etc I feel like there is magic in software
         | too.
        
       | gfaure wrote:
       | It's a beautiful touch that the animation demonstrating the
       | spring itself has a spring action on its playback slider.
        
       | csours wrote:
       | If the author is reading this: A great addition would be common
       | breakdown reasons, perhaps on another page.
       | 
       | Something I didn't really think about until recently: solid metal
       | bearings are used on the crank and piston journals as they can
       | handle more force than ball or roller bearings. In other areas,
       | ball and roller bearings are used to minimize energy loss.
        
         | [deleted]
        
       | incomplete wrote:
       | as someone who as a hobby occasionally builds engines (for the 24
       | hours of lemons), i was really impressed at how incredibly
       | accurate and detailed this whole page is.
       | 
       | i'm down w/TDC...
        
         | mgarfias wrote:
         | I wasn't. But then I've literally been working on engines since
         | i was a little kid.
        
           | addison-lee wrote:
           | Quality contribution!
        
             | mgarfias wrote:
             | so was your mom
        
       | publicola1990 wrote:
       | What tool is being used for the interactive animations? They are
       | really impressive.
        
       | lambdatronics wrote:
       | Really nice work! Reminds me of some of Bret Victor's stuff.
       | 
       | The graph saying that the velocity curve of the piston is
       | asymmetric left-right is wrong. It should be top-bottom
       | asymmetric instead. They got the text right though. Edit: oops,
       | _I 'm_ wrong... the position curve would be left-right symmetric
       | while being up-down asymmetric, but then if you take the
       | derivative you get what they are showing.
        
       | Techasura wrote:
       | Beautiful article. If at all, mechanical engineering was this
       | beautiful.
        
       | mgarfias wrote:
       | ok, and?
        
       | nemo44x wrote:
       | What are the odds 50 years from now, the ICE becomes a hobby of
       | the upper middle and upper classes? Much like analogue audio
       | recording is becoming.
        
       | userbinator wrote:
       | Those who are curious about the oval piston skirts may find this
       | interesting: https://news.ycombinator.com/item?id=15397926
        
       | RaiausderDose wrote:
       | brillant explanation. I always wanted to know how an engine
       | really works.
        
       | B1FF_PSUVM wrote:
       | Hat off, deep bow. Haven't seen such clarity of exposition in
       | decades, if ever.
       | 
       | Pity it's about technology on the way out, but hey, "perfection
       | is achieved on the edge of collapse".
       | 
       | P.S. Learned a few things, and I'm even more amazed that all this
       | actually works and gets things moving at over 100 mph ... looks
       | like a very clever Rube Goldberg joke.
        
       | arendtio wrote:
       | I like the detailed explanations and animations. It reminds me of
       | another page, which doesn't look as polished, but has a few
       | additional designs:
       | 
       | http://animatedengines.com
        
       | nxpnsv wrote:
       | It first feels like one of those oversimplified generic how stuff
       | works things. But this is so much better. Really worth reading
       | through.
        
       | yashksagar wrote:
       | great find - i love the one on Cameras and Lenses too, great use
       | of interactivity for pedagogy
        
       | nielsbot wrote:
       | Another great page! I just have one minor complaint: I wish the
       | spaceball rotations always kept the y-axis oriented upwards...
       | That would help me navigate the models much more easily...
        
       | noveltyaccount wrote:
       | This is incredible. I remember the Gears example from the same
       | site, but now with 3D renderings. Great work.
        
       | PinkPigeon wrote:
       | Lots of very insightful comments already, I only have one thing
       | to contribute, which is a spelling correction:
       | 
       | "Since the piston moves down twice and up twice, it does a total
       | of four strokes and the engine we've build is known as a four-
       | stroke engine. Notice that it takes two revolutions of the
       | crankshaft for the piston to do one full cycle of the work as it
       | goes through the four phases: intake, compression, power, and
       | exhaust."
       | 
       | It should be: "the engine we've built", with a 't', not a d.
       | 
       | /pedantry
        
       | shivenigma wrote:
       | This is such a great article man. Love for the effort you put
       | into this article.
       | 
       | I seriously wish I had teachers and schools like this. I used to
       | imagine the four strokes when I was in school but it is very hard
       | to relate all the moving parts and how everything connects
       | together in that age where I've never used a motorcycle or a car.
       | 
       | Thanks for writing this.
        
       | sssilver wrote:
       | Wonderful page. Here's something a bit more poetic on the
       | subject: The man behind the smallest V-12 engine in the world[0]
       | 
       | [0] https://www.youtube.com/watch?v=c1pJIVqCC1E
        
       | nzealand wrote:
       | Haynes sells an excellent Build Your Own Internal Combustion
       | Engine model, which teaches children about all of these concepts.
        
       | fernly wrote:
       | Can't remember where I first learned this, twas years ago --
       | unforgettable names for the four engine strokes:
       | Suck, Squeeze, Pop, Phooey
        
         | FabHK wrote:
         | I know them (almost poetically, though not necessarily
         | politically correct) as:
         | 
         | Suck, Squeeze, Bang, Blow.
        
       | josefresco wrote:
       | If you like these kind of animations, I found this website a
       | while ago: https://jacoboneal.com
       | 
       | *Graphic designer & 3D artist. Creator of animagraffs.com
        
       | anticristi wrote:
       | This is so incredibly amazing! It must have taken tons of time to
       | make it happen.
       | 
       | Looking forward to the same with turbo, intercooler and EGR. :)
        
       | [deleted]
        
       | zmanji wrote:
       | aaaaaa
        
       | maxekman wrote:
       | Seeing the complexity of an ICE in contrast to mechanically
       | simpler and much more efficient electric motors is fascinating.
       | It makes it obvious to me what will persist, and what will become
       | the next steam machine.
        
         | snemvalts wrote:
         | Just goes to show how difficult energy storage is
        
       | ecommerceguy wrote:
       | I really wish as a kid I had something like this to read/watch
       | because the engine (don't call it a motor I've learned from
       | engineers) still confounds me with all of the moving parts and
       | precision. I've found Detroit Diesel videos on Youtube rather
       | satisfying.
        
       | sergeykish wrote:
       | And if want to share wonders of engineering with a kid check out
       | How to Build a Car by Martin Sodomka [1]. Beautiful illustrations
       | (sample on Czech [2]), translated into many languages.
       | 
       | Series also includes How to Build a Motorcycle, How to Build a
       | Plane, How to Build a House, How to Build a Railway. I've got all
       | of them.
       | 
       | [1] https://www.amazon.com/How-Build-Car-high-speed-
       | friendship/d...
       | 
       | [2] https://www.kosmas.cz/knihy/173150/jak-si-postavit-auto/
        
       | hourislate wrote:
       | If you want to take the experience further, I would recommend the
       | following Redline engine rebuild time lapses that Hagerty has.
       | They are mesmerizing and incredible. Their engine re-builder
       | David is a master.
       | 
       | https://www.youtube.com/playlist?list=PLHKCmmH-x9mI1aCu3Xr4_...
        
         | dugditches wrote:
         | That's the one nicer thing of motorcycles, is their simplicity.
         | 
         | This fellows videos are pleasant. In that he makes
         | 'experimental' engines with a very modest shop. Often using a
         | hacksaw and a BBQ. https://www.youtube.com/watch?v=I-Xr1bmbZ_s
        
           | hourislate wrote:
           | Thanks for this. Loved it!
        
       | phpdave11 wrote:
       | This was really educational! I love the design of the webpage,
       | and I especially like how you can rotate the 3d diagrams and see
       | each component from every angle.
        
         | randlet wrote:
         | If anyone is looking for a hands on educational model, my 6
         | year old and I put together a model V8 engine [1] (made by
         | Haynes of technical manual fame I think) that does a pretty
         | reasonable job of capturing the essence of the main parts of an
         | internal combustion engine. It kept him (and me) thoroughly
         | engrossed for a few hours.
         | 
         | [1] https://www.themotorbookstore.com/build-your-
         | own-v8-engine-m...
        
         | Syonyk wrote:
         | I had _no idea_ until I read your comment that you could click
         | and drag the engine models! Insane!
        
           | sillysaurusx wrote:
           | Ditto. Thanks.
        
           | jiofih wrote:
           | The text immediately before the first image says "You can
           | drag it around to see it from other angles". Our attention
           | spans are deteriorating quickly...
        
             | [deleted]
        
       | specialp wrote:
       | I just built an engine for my car. One thing I gained an
       | appreciation for was how CHEAP cars and engines are. There's
       | probably nothing else with as precise machining that is as
       | inexpensive.
       | 
       | Engine cylinders are honed to accuracies that are less than 1
       | thousandth of an inch. Crank journals as well and rod journals.
       | This is all precise machine work with metal. I use inches here
       | because in machine work thousandths of inches is the language du
       | jour. Transmissions are similar works of very precise and clean
       | machine work.
       | 
       | The distance between a crank bearing or rod bearing is less than
       | 2 thousandths on modern engines. A small amount of oil in that
       | tiny space is all that keeps your engine from having metal on
       | metal seizure.
       | 
       | So one would think that when EVs reach the same scale they will
       | be significantly cheaper than ICE vehicles.
        
         | mfer wrote:
         | If people were willing to pay the higher cost for the same
         | feature set, why would they well them for cheaper? Why not
         | pocket the extra profit?
         | 
         | I don't like this line of thinking but I'm sure it's going to
         | or already is happening.
        
           | clairity wrote:
           | competition, a bedrock element of fair markets, capitalism,
           | and efficient economic allocation, something we seem to have
           | collectively lost sight of.
        
           | admax88q wrote:
           | ...
           | 
           | Because the whole nature of market competition? People will
           | still choose the cheaper option if its available.
        
             | ianai wrote:
             | I'm starting to think it may just be minimizing cost.
             | Theoretically that just means "maximize profit", but I
             | suspect in practice it means a whole slew of bad behavior
             | and design choices. I.e. Pay for the part that's .0001 cent
             | cheaper than another option, despite the cheaper part
             | possibly being a fire hazard.
        
         | swiley wrote:
         | I've always felt cars were like computers; most people (me
         | included) pay a premium for something mediocre because they
         | don't want to bother understanding it.
         | 
         | My personal solution is to live near the metro and bike as much
         | as possible.
        
           | jacobsenscott wrote:
           | Mediocre in what way? Buy almost any new car from a well
           | known brand today and it will run for 200,000+ miles. You
           | almost need to deliberately buy a mediocre car. Biking and
           | taking the metro is better for the environment, your health,
           | and your budget though. If you are fortunate enough to have
           | that option.
        
         | pram wrote:
         | I think automatic transmissions are more impressive looking
         | than engines when they're open. They resemble EV motors too!
        
           | Ambroos wrote:
           | VW group has a dual-clutch automatic transmission that
           | includes an EV motor for their plug-in hybrids, the DQ400E.
           | It looks pretty cool indeed!
        
           | benlivengood wrote:
           | Automatic transmissions also have hydraulic logic gates in
           | the valve body (implemented with check-balls and piston
           | servos), even if they're also electronically controlled.
           | Drag-racers will reprogram the valve body to change the shift
           | order, have launch control, etc.
        
         | elihu wrote:
         | The raw materials may continue to cost more for EVs. Motor
         | windings are generally copper, and batteries contain lithium
         | and (usually) cobalt and nickel. Permanent magnet motors
         | sometimes contain rare earths.
         | 
         | One could make an EV with aluminum motor windings and
         | electrical cabling, no rare earth magnets, and lithium iron
         | phosphate batteries. That would keep expensive materials to a
         | minimum.
         | 
         | EVs don't need a catalytic converter, so that's a big thing in
         | their favor.
         | 
         | I'm looking forward to mass manufacturing continuing to bring
         | down EV component prices. I think we're a long ways from the
         | point where material costs are the bulk of the expense.
        
           | Robotbeat wrote:
           | Tesla already uses aluminum for power cabling because it's
           | cheap and lighter weight. Tesla Model S were induction motors
           | (at first at least) with no rare earths, and Tesla is
           | partnering with CATL for lithium _iron phosphate_ batteries
           | in lower cost versions of, if I believe, Model 3 and Y.
        
             | rsync wrote:
             | "Tesla already uses aluminum for power cabling because it's
             | cheap and lighter weight."
             | 
             | Ugh, really ? That offends my sensibilities ...
        
               | Robotbeat wrote:
               | Why? A properly engineered aluminum power cable is
               | superior to a copper one when weight is at a premium.
        
               | kube-system wrote:
               | Aluminum is less ductile and prone to galvanic corrosion.
               | It can definitely be engineered to work properly, but
               | copper is much more forgiving.
        
             | esaym wrote:
             | Note to replace copper wiring with aluminum, you have to go
             | up at least one gauge size.
        
               | elihu wrote:
               | Yeah, aluminum is a worse conductor so you need thicker
               | cable. It's less dense, though, so I think it usually
               | comes out as being lighter. Thicker cables can be more
               | inconvenient. I think aluminum also tends to have more
               | problems with oxidation causing too much resistance at
               | electrical contacts.
               | 
               | I think for motors generally you just end up with a
               | larger motor for the same amount of power.
        
               | Bubbadoo wrote:
               | All points you make are very true. In addition, aluminum
               | tends to crack as it ages and you'll find aluminum wiring
               | is usually a culprit in electrical fires. In the world of
               | mobile electronics, it's usually looked down upon as the
               | cheapest alternative when compared to real copper
               | conductor used in higher quality automotive wiring.
        
               | Robotbeat wrote:
               | It only requires proper engineering of the connection.
               | Aluminum itself doesn't crack in properly engineered
               | joints. What fails in old houses is shoddy connections.
               | 
               | If people look down upon it, it's because they're either
               | lazy or ambivalent. It's the superior performance
               | solution in some situations.
        
               | CamperBob2 wrote:
               | Or raise the voltage at the same time you change from Cu
               | to Al.
        
             | elihu wrote:
             | I thought CATL makes lithium iron phosphate batteries, and
             | lithium sulfur hasn't been commercialized yet. Unless
             | there's some news on that front I missed?
             | 
             | I think induction motors tend to be less efficient than
             | permanent magnet motors (and thus require more cooling).
             | The Netgain Hyper9 (a popular motor for conversions) is a
             | permanent magnet motor which doesn't use rare earths. It's
             | very efficient but not particularly powerful (though that
             | may be due more to the relatively low voltage it runs at).
             | 
             | That's cool that Tesla is using aluminum for power cables.
             | Makes sense to save cost and weight where you can.
        
               | Robotbeat wrote:
               | Yes, I meant iron phosphate. (I've had sulfur on my mind
               | from Bye Aerospace's 925km range 8-seat electric
               | aircraft, working with Oxis Energy.)
        
           | esaym wrote:
           | > EVs don't need a catalytic converter, so that's a big thing
           | in their favor.
           | 
           | I feel there is some sort of scam going on with catalytic
           | converters for the last few years. I actually worked in a
           | small family owned auto shop in the early 2000's. If a car
           | came in with a clogged cat, we'd first fix the source of the
           | issue (usually a mis-firing cylinder allowing raw fuel into
           | the exhaust) and then we'd cut out the cat, and weld in a
           | universal fit one that we'd get from the auto store for $20.
           | Then charge the customer $200-$400 for labor. I still see
           | universal fit ones[0] although they are $80 now. But still,
           | if you aren't dumping raw fuel or oil into your exhaust, cats
           | are basically good for 300k+ "normal" driving miles. I assume
           | they are expensive now because they are all mostly specially
           | made/custom fit since all car manufactures keep cramming
           | bigger and bigger engines into smaller and smaller spaces.
           | 
           | And while I'm ranting, there's always a negative for every
           | positive and no doubt for the catalytic converter. For a
           | catalytic converter to convert "greenhouse gases", the engine
           | has to be burning fuel at a perfect air:fuel ratio of 14.7:1.
           | While cruising down the highway, an engine could easily save
           | fuel by running a more lean mixture, but this would cause
           | more "greenhouse gases" to go out. So choose your poison I
           | suppose.
           | 
           | [0] https://imgur.com/a/7X0sPlk
        
             | buran77 wrote:
             | On the other hand the quality and performance of those $80
             | catalytic converters are questionable at best. They have
             | neither the longevity, nor the performance of the original
             | part. They might last even 10 times less, and they're
             | usually just barely good enough to pass the emissions
             | tests, which is already the lowest bar to pass given how
             | all manufacturers optimize for that. Real life emissions
             | are far worse.
             | 
             | And the purpose of the catalytic converter is to make sure
             | the CO, NOx, and unburned fuel are _rapidly_ oxidized to
             | CO2, N, and water before leaving the exhaust system. The
             | outcome is that you will produce more greenhouse gases but
             | fewer compounds that are more immediately dangerous to
             | people, especially in cities. So it reduces localized
             | pollution at the price of more CO2.
        
             | scythe wrote:
             | Catalytic converters don't reduce greenhouse gases. Their
             | function is to reduce _poisonous_ gases: NO, NO2, O3, CO,
             | HO2, and sometimes HCN and H2CO. The good news is that all
             | of these compounds are thermodynamically unstable so a
             | catalyst can destroy them.
             | 
             | I don't know where you got the 14.7:1 number but I am
             | certain that NOx are unstable at any concentration (at or
             | near STP) and will always be depleted by a catalyst.
             | 
             | Another commenter is unsure whether the NOx or some GHGs
             | should be reduced preferentially. To clarify: CO2 can't be
             | removed, it is stable; only CH4, N2O and O3 can be removed,
             | and they are not present at relevant levels (except ozone
             | which is poisonous) anyway. The poisonous gases are far
             | more important -- NOx pollution alone kills thousands of
             | people every year (statistically, considering excess deaths
             | as correlated to air pollution).
             | 
             | The increased price of catalytic converters is partially
             | related to the supply of palladium, which experienced a
             | glut following the collapse of the USSR. The Soviet
             | palladium ran out in 2012:
             | 
             | https://www.mining.com/russias-stockpiles-said-to-be-
             | deplete...
        
               | sbierwagen wrote:
               | >I don't know where you got the 14.7:1 number
               | 
               | The cat has to be hot to catalyze. The engine is run rich
               | so unburnt fuel makes it to the cat and is combusted
               | there, warming it up enough to also kill the undesirable
               | gases. This is wasted heat... unless you mount a
               | turbocharger _after_ the cat, which has its own set of
               | weird tradeoffs. (I 've never heard of a factory car with
               | a rear turbo)
        
             | golemiprague wrote:
             | The reason is the increasing price of Palladium which is
             | used by catalytic converters and your dentist. That's why
             | there is huge increase in theft of those converters as the
             | material is scraped and sold in the black market.
        
             | elihu wrote:
             | I don't think cats are to address greenhouse gasses;
             | they're focused more on reducing pollutants that affect
             | local air quality and human health.
             | 
             | The main greenhouse gas from a car is carbon dioxide. The
             | amount you create is directly proportional to the amount of
             | fuel you burn.
             | 
             | I don't know why modern cats are expensive; it might have
             | to do with the price of platinum, palladium, and so on, and
             | the relative amount of those materials. A cheap generic cat
             | might have the bare minimum amount of catalyst, and might
             | not do a very good job.
        
               | czinck wrote:
               | > I don't think cats are to address greenhouse gasses;
               | they're focused more on reducing pollutants that affect
               | local air quality and human health.
               | 
               | I thought the same thing, but interestingly that's only
               | kinda true. If anything, cats increase CO_2 as a desired
               | end goal, because it's better to have CO_2 than CO or
               | NO_x (or so the EPA has decided, I am no where near
               | qualified to decide that). The issue with running too
               | lean is that the reactions in the cat would rather use
               | plain O_2 than NO_x, and so if you have too much O_2
               | (lean) you won't get rid of any of the NO_x [0]. Before
               | looking into this I thought lean engines produced more
               | NO_x because of higher cylinder temps or something like
               | that (which might be true as well).
               | 
               | Cats not reducing NO_x when lean is essentially why
               | Volkswagen (and practically every other manufacturer has
               | been caught doing similar things to diesel engines) was
               | cheating the test. Diesels have no throttle so they are
               | (almost) always lean, typically very lean.
               | 
               | This does make me wonder, though, does running lean
               | actually increase fuel efficiency? Obviously rich lowers
               | fuel economy because not all the fuel burns, but assuming
               | it all burns what does it matter if you have 1 gram of
               | fuel to 15 grams of air in the cylinder, or 1 gram of
               | fuel to 18 grams of air in the cylinder? You'll still get
               | the same amount of energy, right?
               | 
               | [0]
               | https://en.wikipedia.org/wiki/Catalytic_converter#Three-
               | way
        
               | baybal2 wrote:
               | Diesels with combined SCR-EGR can go below US limits
               | rather easily.
        
               | Alupis wrote:
               | > A cheap generic cat might have the bare minimum amount
               | of catalyst, and might not do a very good job
               | 
               | It depends on the car/engine. My old Mazda RX-8 had a
               | _huge_ cat - longer than the muffler and cost me $2,000
               | to replace (including labor) back in the late 2000 's.
               | 
               | The rotary engine in that vehicle had a terribly
               | difficult time passing California's emission laws even
               | when it was brand new off the lot - which led to strange
               | "hacks" including a blower motor that moved high volumes
               | of air through the exhaust to heat the cat sooner and
               | somehow improve it's numbers, among other things. I
               | assume the extra-long cat was part of the shenanigans
               | Mazda had to go through to get it compliant.
        
               | elihu wrote:
               | It's funny you mention the RX-8, since I'm in the (slow)
               | process of converting one to electric. That weird cat
               | blower was one of the many parts I removed while thinking
               | "I'm glad I don't have to understand or care about why
               | this car needed something like that in the first place".
        
               | Alupis wrote:
               | Just talking about the RX-8 brings back great memories -
               | what a strange, yet beautiful car!
               | 
               | The cat blower, and the subtle whining sound it made when
               | you started up cold was one of the ways every RX-8 owner
               | was hazed into the fold... after calling the dealer or
               | posting on a forum and finding out it's entirely normal!
               | 
               | Other oddities included how it deliberately burned oil
               | (scaring new owners into thinking they had a serious
               | engine problem), and how you were required to drive it
               | hard to clear out its engine ports (multiple Mazda
               | mechanics confirmed this factoid) - driving it like a
               | normal car would literally clog up the exhaust ports and
               | cause a loss of power (something to do with the lack of
               | moving valves). If memory serves right, it had only 3
               | (!!!) moving parts in the engine, and was perfectly
               | content to hang out at 9,000 RPM all day - that's
               | incredible.
               | 
               | But, it seems the issues Mazda had maintaining it's
               | emission certifications, and warranty issues with those
               | apex seals (mine had 3 engine replacements over it's
               | lifetime) eventually caused it to be retired. I was sad
               | back then, and still sad we don't have a new improved
               | version - there's really nothing else quite like it out
               | there, not even the RX-7. It really was/is an
               | enthusiast's car.
               | 
               | Good luck on your project - sounds like a fun one!
        
               | elihu wrote:
               | I'm hoping LiquidPiston's rotary engine design pans out:
               | https://news.ycombinator.com/item?id=25450477
               | 
               | In theory, it should fix some of the maintenance issues
               | (apex seals are attached to a stationary part of the
               | engine where they can be more easily lubricated) and fuel
               | efficiency / emissions issues (combustion chamber is
               | closer to spherical).
               | 
               | I like the idea of the Mazda rotary engine, but I'm not
               | really surprised they stopped making them, due to fuel
               | economy and emissions. And at them moment, the hundred-
               | thousand mile engine rebuild interval basically means you
               | can get an RX-8 with a bad engine for almost nothing,
               | which opens up a nice opportunity for EV conversion. It's
               | hard to imagine a nicer platform to start from.
        
               | Alupis wrote:
               | Wow, that LiquidPiston rotary looks very interesting! I
               | hadn't seen that before - I too hope it pans out.
               | 
               | > I'm not really surprised they stopped making them, due
               | to fuel economy...
               | 
               | Eh, nobody bought that car for the fuel economy!
               | 
               | The car sold itself... just one test drive and you _had_
               | to have it. I 've owned and driven muscle and other
               | sports cars, and still nothing compares to the RX-8 -
               | it's just such a unique experience.
               | 
               | Not sure how you're doing the conversion, but if you're
               | keeping the carbon fiber driveshaft (vs. a motor on each
               | wheel I suppose), there will be nothing keeping it from
               | screaming off the line with an electric motor under the
               | hood (traditionally the wankel wasn't good off the line
               | with low RPM's, power band kicking in around 6500 if I
               | recall - could make for a great "sleeper"). Although I'm
               | unsure if the driveshaft would stand up to the torque a
               | motor would output, since the wankel wasn't particularly
               | torquey.
               | 
               | If you're not already, keep a blog and pictures of the
               | conversion - that would make for an interesting read!
        
               | elihu wrote:
               | > Eh, nobody bought that car for the fuel economy!
               | 
               | True enough, but I'm sure there are other factors in
               | play, such as public policy. Fuel economy standards have
               | been going up.
               | 
               | The motor I'm putting in my conversion is a Netgain
               | Hyper9 (high-voltage, double-ended shaft version). It's
               | about 120 horsepower and less than 200 foot pounds of
               | torque, so in theory the clutch/transmission/driveshaft
               | should be fine. (I'm keeping the 6-speed transmission.)
               | It probably won't be particularly fast, but we'll see.
               | More powerful AC motors exist, but they tend to be
               | expensive.
               | 
               | I haven't posted any pictures yet; I've been meaning to,
               | just haven't gotten around to it. There's another guy in
               | the UK I think with a youtube channel that's doing close
               | to the same thing, but with a Leaf motor.
        
               | kube-system wrote:
               | > moved high volumes of air through the exhaust to heat
               | the cat sooner and somehow improve it's numbers
               | 
               | This is because the catalyst works more efficiently at
               | higher temperatures. Emission regs also test vehicles
               | under a cold start. The quicker the cat can be heated up,
               | the quicker it starts working, and that equals fewer
               | total emissions over a given period of operation.
        
           | the_cat_kittles wrote:
           | cmon man. the total weight of pricey metals in a car is so
           | low, there is no way its going to offset the cost of
           | precision machining. tolerances < 1 thou and callouts for
           | surface finish and perpendicularity are expensive!
        
             | jeffreyrogers wrote:
             | I'm sure a motor is cheaper than an engine (less steps to
             | make), but they still require precision manufacturing, and
             | all the other parts aside from the motor (driveshaft,
             | axles, brakes, etc.) are more or less the same.
             | 
             | Plus, the cost of those other materials is going to
             | increase if demand for EVs goes up.
        
               | the_cat_kittles wrote:
               | evs could drive lithium but i really doubt they would
               | influence copper that much, since it is used so much
               | already
        
               | jeffreyrogers wrote:
               | I think the more constraining commodities are things like
               | rare earths[0] and other important metals like cobalt.
               | 
               | [0]: I know they aren't that rare, but they aren't
               | mined/processed in many places and it takes a long time
               | to bring a new mine online.
        
             | elihu wrote:
             | Somehow car manufacturers are able to make engines,
             | transmissions, transaxles, and differentials really
             | cheaply, so apparently all that precision manufacturing
             | doesn't really cost all that much when producing at high
             | volume. This should be equally true of EVs and combustion-
             | engine cars.
             | 
             | Raw material costs might still be less than the
             | manufacturing costs, but they're pretty hard to avoid.
             | Also, materials that are cheap now might not be if demand
             | grows faster than supply.
        
             | jbay808 wrote:
             | Hard to say. Those tolerances would be expensive in general
             | purpose machine work, but in engines those tolerances have
             | been in place since at least the 1930s, and so economies of
             | scale bring those costs down (ie, using specialized
             | machines that are _really good_ at boring precision holes
             | and measuring them. The costs of those machines get
             | amortized over every engine).
        
         | kokanator wrote:
         | Anyone who has the inclination to build an engine, should.
         | 
         | It is super rewarding not to mention you get to buy a bunch of
         | really cool tools.
         | 
         | I build a 350 Windsor from the block. The research and design
         | decisions were one of the best parts of the project. Then to
         | put it all together and realize the power was amazing.
        
           | Prcmaker wrote:
           | Ford (Aus) 4.0 was a great first build for me. I'm now taking
           | my time on a Toyota 4K 1300cc, learning a lot more, and
           | taking the time to design new components for it. Can't
           | recommend it highly enough, though not for everyone to be
           | sure.
        
         | formerly_proven wrote:
         | > I use inches here because in machine work thousandths of
         | inches is the language du jour.
         | 
         | Only in the USA ;)
        
           | alexvoda wrote:
           | The rest of the world figured that using prefixes with a
           | predefined universal multiplier is more practical.
           | 
           | Therefore you can use the milifoot equal to a thousandth of a
           | foot, or the kiloinch equal to one thousand inches, or the
           | microyard equal to one millionth of a yard, maybe even the
           | centifurlong equal to one hundredth of a furlong.
           | 
           | We are quiet proud of our prefixes. Now if only we would
           | decide on a single reference unit to which to apply the
           | prefixes. Conversion from megainch to hectofurlong is rather
           | inconvenient.
        
         | CRConrad wrote:
         | > I use inches here because in machine work thousandths of
         | inches is the language du jour.
         | 
         | I'll make a wild guess: In the USA.
         | 
         | EDIT: Heh, sorry... See
         | https://news.ycombinator.com/item?id=26991690 . This time I
         | really thought I'd checked, but there was _lots_ of catalyst
         | talk in between.
        
         | ryandrake wrote:
         | Not only the tight measurements, but I've always been amazed at
         | the precise timing of all the little moving parts, the valves
         | all opening and closing at precise to-the-millisecond times so
         | that each stroke happens, at 6000 RPM! So impressive.
         | Especially with an interference engine, where getting that
         | timing wrong means bent valves.
        
           | globular-toast wrote:
           | Mmm.. not really. It's just a cam and a spring. Pretty easy
           | to get that bit working by yourself. Variable valve timing
           | and lift is much more impressive.
        
         | slver wrote:
         | How about your phone.
        
         | kccqzy wrote:
         | > One thing I gained an appreciation for was how CHEAP cars and
         | engines are. There's probably nothing else with as precise
         | machining that is as inexpensive.
         | 
         | Not to denigrate the amount of engineering that went into car
         | engines, but literally, what about chips? Devices that contain
         | billions of transistors, arranged precisely on the order of
         | nanometers. Yet they cost only hundreds of dollars.
        
           | akiselev wrote:
           | They're apples and oranges. Chips are not machined, they're
           | etched in batches. Their "tolerances", so to speak, are
           | limited by the wavelengths of visible or UV light they use
           | for creating the masks and exposing the photoresist that
           | protects the wafer from hydrofluoric acid and other etchants.
           | There's no mechanical force involved, except to spin wafers
           | to apply coatings and move them between each stage of the
           | process.
           | 
           | Engine blocks, on the other hand, are CNC machined one at a
           | time and the force of machining steel causes vibrations that
           | move the cutting tools thousands of nanometers back and
           | forth. Placing both in the same building, for example, would
           | likely cripple the semiconductor fab. Having a machine shop
           | in China make a one off would likely cost as much as a luxury
           | car.
        
           | specialp wrote:
           | Yes you are referring to another insanely complex thing that
           | is very cheap relative to making one of cost due to mass
           | production. But it isn't machined metal :) I didn't say I
           | don't appreciate electronics too.
        
         | Animats wrote:
         | _I just built an engine for my car. One thing I gained an
         | appreciation for was how CHEAP cars and engines are. There 's
         | probably nothing else with as precise machining that is as
         | inexpensive._
         | 
         | When cars started getting electronic engine controls, there was
         | much internal grumbling about the cost. One Ford production
         | guy, on hearing that the engine controller cost about $100,
         | said "I can make the whole engine for 100 bucks."
        
         | kingsuper20 wrote:
         | >So one would think that when EVs reach the same scale they
         | will be significantly cheaper than ICE vehicles.
         | 
         | I expect that batteries are the only hangup, there's probably
         | not that much magic left in an electric motor. Additional cost
         | for regen brakes of course.
         | 
         | I agree on the amazing cheapness of it all if you stick with
         | the common stuff. That, along with the low cost of flat panel
         | TVs is a miracle of the modern age.
        
           | londons_explore wrote:
           | > Additional cost for regen brakes of course.
           | 
           | Regen braking has no physical cost associated - it's pure
           | software/firmware. The _exact_ same hardware that is used to
           | power the car forwards can be used for regen braking. It can
           | be as simple as a single negative sign in the code to cause
           | the phase to be 180 degrees out, current to flow backwards,
           | torque to go the other way, and the battery to be charged
           | instead of discharged.
           | 
           | One day regen braking will take over hydraulic brakes, and
           | another big cost/complexity of a car will be eliminated. The
           | only reason that doesn't happen today is there are lots of
           | laws and regulations requiring hydraulic brakes, and braking
           | systems typically require more redundancy than power systems.
        
             | distortedsignal wrote:
             | > Regen braking has no physical cost associated - it's pure
             | software/firmware.
             | 
             | I think this is a slight exaggeration.
             | 
             | The way I understand regenerative braking is that you
             | (effectively) run your AC generator in reverse of what you
             | would in order to accelerate in the direction of motion and
             | then take the current generated by that, rectify it to DC,
             | and use that current to charge a battery. The energy in the
             | system is provided by the back EMF induced in the stator by
             | the magnetic field generated by the motor rotor. I agree
             | that the AC generator is going to stay the same, but I
             | think there's specialized hardware needed for the
             | rectification and charging cycles. At the minimum, you need
             | a more specialized battery and battery management system to
             | make sure that you're balancing the charge across the cells
             | in your battery.
        
               | labawi wrote:
               | I think you are overestimating unique requirements of
               | typical car engines. They are usually DC powered AC
               | engines, where the DC->AC converter (generating 3-phase
               | AC of controlled power and frequency) can probably run
               | backwards (AC->DC) with at most a few minimal hardware
               | changes, if any.
               | 
               | If you're not overdoing regen, you probably don't need
               | additional balancing. Even if you wanted to charge the EV
               | by towing, you could probably use the normal charge
               | balancing circuitry, again minimal if any HW changes.
               | Non-wimpy batteries and cells should be fine - if they
               | can fast-charge, they can take regen. Might have some
               | limitations on acceptable power vs. temperature, charge
               | state etc.
        
               | [deleted]
        
             | kingsuper20 wrote:
             | Is that right? I didn't know that. I'd like to see a BOM on
             | a regen braking as compared to a simple disk brake system.
             | 
             | One implication to software-only brakes is that it requires
             | that that corner is a drive wheel. If that's the case, I
             | suppose that anti-lock is simply firmware and a sensor.
             | 
             | note: I do see that Teslas have master cylinders, so they
             | apparently are hydraulic braking systems.
        
               | dahfizz wrote:
               | A bill of materials? As OP said, there is _literally_
               | nothing required aside from what is required to make the
               | car go forward. An electric motor is a generator.
               | 
               | Teslas have traditional braking systems in addition to
               | the regen braking. The hydraulic brakes have nothing to
               | do with the regen system.
        
               | kingsuper20 wrote:
               | I appreciate that now. Thank you to everyone for the
               | education.
               | 
               | >The hydraulic brakes have nothing to do with the regen
               | system.
               | 
               | I strongly suspect that they interact for antilock.
               | 
               | I wonder how Teslas deal with parking brakes,
               | historically kind of an issue with disks.
               | 
               | It does seem to me that an entirely regenerative braking
               | system would imply additional expense in terms of the
               | strength of the half shafts, u-joints, transmission if
               | any.
        
               | specialp wrote:
               | Parking brakes for disc brakes are usually in the center
               | of the disc rotor (like a mini drum) with shoes. Some
               | others like Chryslers have implemented hybrid brake
               | cylinders
        
             | cesarb wrote:
             | > One day regen braking will take over hydraulic brakes,
             | and another big cost/complexity of a car will be
             | eliminated.
             | 
             | I have read somewhere that the regenerative braking is much
             | less effective when the car is going really slow, so you
             | still need the hydraulic brakes to come to a complete stop.
        
               | londons_explore wrote:
               | True, but you can also use a tiny bit of battery power to
               | do "reverse acceleration" to do the final stopping.
               | 
               | It is true that electric braking would continuously use a
               | small amount of power to stay stopped on a slope. That
               | wouldn't be an issue for a few hours, but you couldn't
               | park on a hill for months without ending up with a flat
               | battery, and then eventually the car rolling away.
               | 
               | Small locking pins are the answer to this, rather like
               | the "park" on automatic gearboxes. They are very cheap,
               | since they don't need to do any actual stopping, but
               | merely keeping something stopped.
        
           | mfer wrote:
           | > I expect that batteries are the only hangup,
           | 
           | Batteries are a huge hangup. For example, we don't know how
           | to recycle them and they aren't good for dumps. And, used car
           | batteries are expensive to replace and you get a lot fewer
           | miles per charge out of older cars. Manufacturing of cars
           | isn't great for the environment so we should want older cars
           | to last. This model helps push people to more new cars
           | faster.
        
             | kingsuper20 wrote:
             | No problemo. Just go to a big honkin' flywheel somewhere
             | under the back seat.
        
               | stjohnswarts wrote:
               | there have been flywheel (only) powered vehicles made.
               | https://en.wikipedia.org/wiki/Gyrobus
        
           | B1FF_PSUVM wrote:
           | > the low cost of flat panel TVs is a miracle
           | 
           | That's really astounding, I just looked at a 55 inch brand
           | name 4k TV going for 400 bucks retail.
           | 
           | Guess it's the same logic as cramming more CPU, etc. into the
           | usual couple hundred sq. mm chip. But you get more CPU for
           | the same money and chip size, which is not as spectacular as
           | more screen size for less money ...
        
           | [deleted]
        
           | piva00 wrote:
           | > there's probably not that much magic left in an electric
           | motor.
           | 
           | I believe this sentence has been said about many technologies
           | in the past that definitely invalidated it. I'm more playing
           | devil's advocate than trying to falsify you, likely for being
           | burned sometimes reading or, worse, stating it, haha.
        
             | londons_explore wrote:
             | There isn't much more _efficiency_ to be gained in the
             | electric motor world. Motors typically get 90% of
             | theoretical efficiency, so any improvements there will be
             | modest.
             | 
             | Substantial improvements in other metrics might be had, but
             | they probably won't massively impact EV's (weight and costs
             | of the motor are both a small part of the total for a car)
        
         | gtvwill wrote:
         | > "I use inches here because in machine work thousandths of
         | inches is the language du jour."
         | 
         | Yeah not in Australia unless your machinist is >50 years old.
         | Metric is more accurate/easier/less prone to mistakes. Metric
         | is what we use.
        
           | specialp wrote:
           | I'm not denying the metric system. Just in the USA it is thou
           | period. and if the measurement is a consistent unit of
           | whatever it works. Also GM (and Holden in oz) are inch based.
           | So using metric will subject you to mistakes possibly. I
           | agree though in science SI is the way to go
        
             | gtvwill wrote:
             | Yeah I cut my teeth on Subaru engines (helped having a gf
             | who was a subi then telsa mechanic walking me through it).
             | Subi are all metric tho. My workshop is a mix of metric for
             | new gear and imperial from my old mans days running a farm.
             | 
             | We even have some stuff thats neither metric or US
             | imperial, but is british witworth imperial...so different
             | again and just enough to make a difference. Makes for some
             | confusing repairs when your working with stuff that's had a
             | mix of all 3 systems due to a long life of repairs.
        
           | jabl wrote:
           | I'm in Europe, and I've had/worked on German, Japanese and
           | Swedish cars and boat engines. Metric all the way.
           | 
           | Only time I've needed an imperial set of tools was when
           | overhauling a B&S lawnmower engine.
        
           | Prcmaker wrote:
           | I was trained in Australia, in the past decade, and was
           | taught thoroughly in both metric and imperial. The engineers
           | and machinists I have worked with that insist metric is the
           | only way habe been more prone to mistakes when imperial
           | components pop up, as they do. Accuracy is down to the spec,
           | the person and the machine, ease of use is identical when
           | decimal inches are used, mistakes are a result of poor
           | communication.
        
           | s5300 wrote:
           | Still widely used and taught in the machine shops of highly
           | reputable universities over here in the U.S.
           | 
           | If you're under 40 and can't use metric and imperial jargon
           | without a second thought in the shop here that's a different
           | problem. I _personally_ enjoy doing machine shop-esque metal
           | fabrication in metric and woodshop type things in imperial,
           | but all machine shop instructors I 've met through several
           | good stem uni's that look even slightly middle aged love to
           | talk in thou of inch, some to the point of getting quite
           | physically frustrated when asked where the metric drill
           | index/reamer set are in otherwise highly stocked shops...
           | 
           | Also, I've noticed and heard the same from others in
           | surrounding states - Fluid Dynamics professors love to
           | include absolutely unecessary boatloads of strange units and
           | conversions in coursework/exams to apparently "prepare us for
           | the shitshow that is industry"
        
         | tmh88j wrote:
         | Nice! What engine did you build?
         | 
         | >The distance between a crank bearing or rod bearing is less
         | than 2 thousandths on modern engines. A small amount of oil in
         | that tiny space is all that keeps your engine from having metal
         | on metal seizure.
         | 
         | The BMW S65 and S85 engines are prime examples of what happens
         | when the wrong tolerances are chosen. I can't think of another
         | engine family where rod bearings are considered a maintenance
         | item.
        
           | specialp wrote:
           | I built an LSX (Aftermarket GM) iron block engine (V8 LS) for
           | a CTS V. I had to get some very precise tools (Have to
           | measure to 10,000ths) or they were useless for bearing
           | clearances and verifying cylinder diameters. My cylinders
           | were 4.155 bore, and the bearing clearances were around 1.8
           | thousandths. Forged pistons, rods and crank.
           | 
           | I had cracked a cylinder/piston on the original LSA. I did
           | not trust anyone to do the work so I did a lot of research
           | and did it all myself. I appreciate someone asking because my
           | friends and software dev co workers aren't interested :)
        
             | kingsuper20 wrote:
             | Very cool. Although I own an LS, I've never touched an LS.
             | The Sloppy Mechanics guy is impressive though.
             | 
             | Since a short block is mostly just a short block, I'll be
             | interested in seeing if LS heads/intake manifold/headers
             | takes off in the SBC community.
        
               | mgarfias wrote:
               | Huh? What do you mean "takes off". Do you mean do we
               | build LS motors now instead of gen1/2 SBCs then yes.
               | 
               | If you mean "do the LSx heads drop onto a gen1/2 SBC",
               | then no, not at all. only thing common between them is
               | the cylinder spacing. The LS uses 4 bolts per cylinder
               | like a ford, instead of 5 like the SBC, the firing order
               | is different, the valve layout is different (ports are
               | symmetric vs mirrored), etc.
        
               | kingsuper20 wrote:
               | Firing order is something of an arbitrary thing, it's
               | been done on SBC for some time.
               | 
               | There are small block Chevrolet blocks that accept LS
               | heads (Bill Mitchell maybe?)
               | 
               | (note: I wasn't referring to box-stock LS heads on a box-
               | stock SBC)
        
               | mgarfias wrote:
               | Mostly what i've seen is making the SBC take a
               | symmetrical head. Saw some INSANE CFE pro stock heads at
               | the machinist last year, he was building them in a large
               | bore, short stroke deal setup for bonneville to run like
               | 11krpm.
        
             | Grazester wrote:
             | Why did you go iron block for your build? Is it that your
             | were afraid you cracked the block again? How did you do
             | that in the first place. Are you running any boost on this
             | engine?
        
               | specialp wrote:
               | I'm running 14 lbs boost yes. And yes it was piece of
               | mind that it's much harder to crack and unlike the
               | aluminum block I can bore it more than 5-10 thou if it
               | needed it again. Downside is 100lbs more but this is in a
               | 4200lb car so whatever
        
             | tmh88j wrote:
             | >I had cracked a cylinder/piston on the original LSA. I did
             | not trust anyone to do the work so I did a lot of research
             | and did it all myself
             | 
             | I love working on cars so I totally get wanting to do that,
             | but why didn't you trust someone else to do the work? There
             | are probably more reputable LS builders across the US than
             | any other engine family.
        
               | esaym wrote:
               | It sounds like he wanted some very precise work done.
               | Quality in the blue collar trades has gone to nil in the
               | last decade. And if you do find someone that is very
               | detailed and "by the book" level of quality, you are
               | going to pay 3X the normal labor rate. For instance, this
               | is a performance transmission shop [0] that regularly
               | takes apart "precision" rebuilt transmissions only to
               | find they were not done right at all.
               | 
               | [0] https://youtu.be/aI5iO2YSHMs
        
               | tmh88j wrote:
               | LS engines are among the most common engines in custom
               | built cars, and there are countless shops out there who
               | specialize in them. No offense to him or you, but it's
               | quite ridiculous to believe you can do a better job
               | building an engine on your first try than shops like
               | Texas Speed who have been doing it for decades with full
               | blown R&D labs and regularly build 2000+ horsepower
               | motors, all with highly skilled machinists and engineers
               | using professional equipment that the average person
               | would never be able to afford.
               | 
               | Edit - For reference here's a video of the shop I'm
               | referring to. They're far from a podunk operation.
               | https://www.youtube.com/watch?v=8HgwF5dISmU
        
               | specialp wrote:
               | I could do a better job than them in all due respect. I
               | care about my job more than anyone on earth. I know they
               | do good work but if we could both measure to the same
               | specs and know we did it right, how could I do it worse
               | than them. we have the same measuring tools. Not that I
               | think they do bad work. But if you ever built an engine
               | you know its all about attention to detail. there is
               | nothing they have to verify the integrity of the build
               | that I don't to a similar level of precision.
               | 
               | Edit: I dont have the machines they do, but when my bare
               | block comes back from the machine shop, my tools are just
               | as good as theirs to verify the dimensions are correct.
               | That isn't possible to verify with a built short or long
               | block. They could possibly have 100 employees that care
               | as much about my job as me who knows. This is a job about
               | verification of specs and assembling correctly not of
               | insane tech. They don't have anything I dont when
               | assembling an engine. Machine work yes
        
               | selykg wrote:
               | Texas Speed or TKM are two places I'd use if I were doing
               | an LS build.
        
               | mywittyname wrote:
               | It helps that they are abundant (in the hundreds of
               | millions units produced), have been in use for decades
               | (since the mid-50s), and are simple to work on (as
               | evidence by the OP randomly learning to machine one).
               | 
               | As cool as 2-atom thick plasma transfer wire arc cylinder
               | liners are, that's not something which will ever be
               | available to a layman.
        
               | mgarfias wrote:
               | I really doubt the OP did the machine work himself, those
               | tools are not affordable for just using once or twice.
               | Buying bore gages and mics however is totally doable.
               | 
               | And no, the LS motors have been in use since '97.
               | Including the gen1/2 small blocks doesn't count, there
               | are no shared parts between them.
        
             | specialp wrote:
             | Yes you are right as far as LS engine builders there's
             | loads. I could have ordered a crate engine from Texas Speed
             | and been done with it. And yes for hours of my time spent
             | vs hours of money saved I lost a ton of money. But all it
             | takes is one very small mistake to make an engine short
             | lived with these exacting tolerances. I'd rather blame
             | myself than deal with someone kicking the blame back. It
             | was also a personal satisfaction thing.
             | 
             | My wife's engine had an issue and it was the middle of
             | winter so I said whatever let's just have a shop fix it. In
             | the process they "flushed the transmission" and it failed 4
             | days after we got the car back. Of course they stonewalled
             | us and I can't prove they broke it. So I ordered a late
             | model wreck transmission and replaced it and 3 years later
             | still running strong.
             | 
             | But I then decided that I would never be in that position
             | again where someone could tell me it wasn't their problem
             | and get me aggravated. With this engine I built it from raw
             | parts. I had the block machined, and I had the tools to
             | verify.
             | 
             | It was certainly not worth my time, but as you said I love
             | working on cars too.
        
               | Grazester wrote:
               | I have a buddy that is adamant about not flushing
               | transmissions if you dont have a issue because he think
               | its guaranteed to have an issue after, from his
               | experience. lol
        
               | Severian wrote:
               | There is _some_ truth to that, but not never. A flush
               | will dislodge any metal shavings and crud from the moving
               | parts. The filter should catch these, but the filters
               | themselves can get clogged, and then bye-bye
               | transmission.
               | 
               | Flushing can really be bad if you've never done a routine
               | flush on a schedule. You don't want to go 150,000 miles
               | before your first one. You would need a garage with a
               | forced flush system to move it all out, and then probably
               | flush again soon after to make sure all the gunk is out.
               | 
               | Transmission oil breaks down with heat and wear like any
               | other, and will eventually contain sludge and dirt.
        
               | specialp wrote:
               | I'd concur with that. Note this was one of the notorious
               | to fail JATCO nissan/mitsubishi transmissions. Blowing
               | fluid through with pressure makes no sense. Sediment
               | sitting in pans does not affect operation until it is
               | agitated into suspension
        
               | Grazester wrote:
               | The Nissan automatics and especially manuals(cd009) are
               | fairly strong. It's their CVT that's the issues. I don't
               | know why Nissan insist on using them with their V6's.
        
             | philg_jr wrote:
             | Damn, dropping a new engine in a CTS V? What year? NA? How
             | much power are you shooting for? The CTS V is definitely
             | one of my favorite cars, I'd love to own one one day, but
             | the ones with the manual trans hold their value pretty well
             | :)
        
               | specialp wrote:
               | It was and still will be supercharged. It was 650 crank
               | Hp, and will be over 800 conservatively . and its manual
               | ;)
        
               | philg_jr wrote:
               | Yep. Jealous. Best of luck on the build!
        
             | mgarfias wrote:
             | 17-18 thou here on my LS6 on the rods. 23-24 on the mains.
             | I'd like to see tighter on the mains, but not sure if its
             | worth ordering another set of bearings and using 1/2 of
             | them to tighten up 1/2 a thou like i did on the rods.
             | 
             | what amazes me is the cam lifts we're running these days.
             | I'm running .646"/.649". In the 90s .500" was big for a
             | street motor, and only full blown race motors were running
             | whats normal now.
        
           | kirse wrote:
           | Subaru EJ motors munch through rod bearings quite happily.
        
             | samstave wrote:
             | What are the indicators that replacing them is neigh?
        
               | Prcmaker wrote:
               | In my experience with these, when I've heard the first
               | indicator to do it, the damage is done. Standard regular
               | maintenance hasn't identified the issue in advance. I'd
               | be curious to see whether long term monitoring of
               | particulates in oil can make an help though.
        
           | zeusk wrote:
           | Any race or high power engine, especially those that rev
           | quite high will need rebuild - not just in bottom end but
           | often with piston rings and valves as well.
           | 
           | You don't really hear about those other engines much because
           | their buyers understand that a race engine needs more
           | maintenance than any other road car.
           | 
           | Also, not beating on the engine until oil has warmed up to
           | temp will elongate the bearing lifespan quite a bit. I have a
           | friend with E60 6mt S85 that has factory bearings at 110k mi
           | and has perfect oil analysis results.
        
             | tmh88j wrote:
             | The S65 and S85 are road car engines, not racecar engines.
             | They're also hardly BMW's highest performing motors. Even
             | Dinan built engines don't suffer from that problem.
        
               | zeusk wrote:
               | They're meant to be dual duty. There aren't any road car
               | engines I'm aware of that use individual throttle bodies
               | or 12+ compression without direct injection.
        
               | tmh88j wrote:
               | The S54 engine which came before the S65/85, was also
               | high revving, had 11.5:1 compression ratio and didn't
               | have any of the rod bearing issues. The 20v Toyota 4AGE
               | also had them too with a high compression ratio.
        
               | jcoby wrote:
               | The S54 absolutely had rod bearing issues. There was a
               | recall on the 2001-2003.5 M3s to replace them and BMW
               | switched to 60w oil as part of the remediation. They're
               | still having issues to this day.
               | 
               | The S54 is also notorious for VANOS issues and cam drive
               | failures. I had to replace the solenoid pack on mine but
               | elected to not upgrade the drive while I was in there.
        
               | zeusk wrote:
               | S54 most definitely had rod bearing issues.
               | 
               | 4AGE is 4cyl 11:1 compression producing 155hp with
               | 7200rpm redline.
               | 
               | S85 is 10cyl 12:1 compression producing 500hp with
               | 8250rpm redline.
        
             | esaym wrote:
             | > Also, not beating on the engine until oil has warmed up
             | to temp will elongate the bearing lifespan quite a bit.
             | 
             | I am curious if there is proof to this. I've always felt
             | the same way. I know in the "old days" with iron pistons,
             | if you you simply started up a cold motor and and drove it
             | hard without a warm up period, the pistons would expand
             | quicker than the block and would start to scour the walls
             | and/or lock up.
             | 
             | But other than that, the only other "proof" I have is from
             | people in high school that like clock work at 3:30
             | everyday, would smoke tires leaving the parking lot
             | everyday. They seemed to go through motors every 6 months.
             | I'm talking knocking bearings and lifters cracked in half.
             | I've never gotten rough with anything I own until after a
             | 20 minute "warm up" and all has been well (so far).
        
               | kingsuper20 wrote:
               | It wasn't so much locking up or anything but cast vs.
               | forged.
        
           | Grazester wrote:
           | I thought once you replaced the crappy OEM bearings you were
           | all set on these engines. I guess it is not the case?
        
         | [deleted]
        
       | Sosh101 wrote:
       | This is amazing educational content.
        
       | cbsudux wrote:
       | This is awesome. How did you create the animations?
        
       | qwertox wrote:
       | One of those web pages which deserves an award. Some place in
       | some kind of Internet Hall of Fame, an historical archive which
       | shows the only best highlights of what websites were actually
       | capable of presenting. Milestones of web development.
       | 
       | This page summarizes pretty good what web technology is capable
       | of, when in the hands of a real professional.
       | 
       | ---
       | 
       | Ok, I just realized this is from Bartosz Ciechanowski, and this
       | reminded me of the Cameras and Lenses [1] article which I've seen
       | recently. It was the same kind of quality.
       | 
       | This man is a real genius.
       | 
       | [1] https://ciechanow.ski/cameras-and-lenses/
        
         | cblconfederate wrote:
         | The award is the bookmark. This is a great reference for
         | cleaniness.
        
         | pitspotter wrote:
         | https://ciechanow.ski/cameras-and-lenses/
         | 
         | > [...] We've barely scratched the surface of optics and camera
         | lens
         | 
         | A real genius certainly, but, I'm always doing this; bad choice
         | of metaphor here!
        
           | hutzlibu wrote:
           | "bad choice of metaphor here! "
           | 
           | Or a funny one.
        
         | jonplackett wrote:
         | Love how it's written
         | 
         | > While reliable and easy to direct, a cannon ball won't be
         | very effective at pushing the crank
        
           | ehnto wrote:
           | That was a fantastic metaphor, and though I am intimately
           | familiar with engines I had never thought of the crankshaft
           | as four simple hand cranks stuck together before.
        
             | rz2k wrote:
             | I wonder if it was inspired by well known this classic
             | video explaining differentials.
             | 
             | https://youtu.be/yYAw79386WI
        
         | BlueTemplar wrote:
         | Yeah, and to think that some people are incredulous when I say
         | that I need animation support in my electronic documents !
         | 
         | This is even better, I will bookmark it as an example.
        
           | exhaze wrote:
           | Saw a startup recently building something like "PowerPoint
           | for animated documents" - https://www.unscene.app/
           | 
           | Crazy that no one's made this before
        
             | BlueTemplar wrote:
             | Really cool, but : - For the love of God, why a web app ?!?
             | - We pretty much already have what I'm asking for in the
             | form of MHTML, I just need Firefox support !
        
         | pvg wrote:
         | I like the the interactive visualizations a lot and some of the
         | setup (a camera picture is a thing that changes in certain ways
         | as you fiddle with these 3 parameters, etc). But I always have
         | a hard time telling who the actual _audience_ for this stuff
         | is. If it 's someone who has very little exposure to how
         | cameras actually operate, is a Bayer filter really the second
         | thing they need to be aware of? I don't really follow the
         | pedagogical narrative/intent here.
        
           | [deleted]
        
         | umvi wrote:
         | I'm assuming he used something like SolidWorks to CAD up the
         | parts, but then it looks like he custom made all the animation
         | stepping widgets and camera rotation logic and various shaders
         | for the different effects in pure JS[0]? Surely he didn't write
         | this JS by hand (i.e. it was generated from blender3d or
         | solidworks files or something?).
         | 
         | I would like an article on how he made the interactive
         | animations in the article.
         | 
         | [0] https://ciechanow.ski/js/ice.js
        
           | vishnugupta wrote:
           | > Surely he didn't write this JS by hand
           | 
           | It seems parts of it are auto-generated like all those co-
           | ordinates. But then some parts appear as if they are hand-
           | coded.
           | 
           | I also noticed that other program texts are getting assigned
           | to variables (example "line_vert_src"). Could someone please
           | describe what's going on?
           | 
           | That explosion animation is absolutely mind-blowing. Goes to
           | show what can be achieved if someone focuses their attention
           | to a topic to understand it in depth _and_ explain it at the
           | same depth.
        
             | JW_00000 wrote:
             | > I also noticed that other program texts are getting
             | assigned to variables (example "line_vert_src"). Could
             | someone please describe what's going on?
             | 
             | These are fragments of code in "OpenGL ES Shading
             | Language", passed to WebGL. See for instance [0] for a
             | tutorial.
             | 
             | [0] https://developer.mozilla.org/en-
             | US/docs/Web/API/WebGL_API/T...
        
           | gfaure wrote:
           | I think it can't be understated how important it is to able
           | to rotate, and move the playback forwards and backwards.
           | 
           | It's almost like being able to hold the part in your hands,
           | examine the reasoning behind its structure and "debug" your
           | mental model of it by playing its operation back and forth.
        
             | CaptainBanger wrote:
             | It really reminded me of the educational 'toys' that I used
             | while I was attending Montessori school. You could go at
             | your own speed and come to understand a concept by letting
             | you play with all the constituent parts when you felt like
             | it - or if you saw someone else doing it and joined in.
        
               | jiscariot wrote:
               | One of the 'toys' I remember from my Montessori
               | experience was these long bead chains. They had all
               | different sizes, e.g. one would be a chain of 8 segments,
               | each containing 8 beads on a rod between the joints. The
               | '8' chain would be blue and have an associated blue cube
               | of beads 8x8x8. I remember the '10' chain and cube was
               | something really to be seen.
               | 
               | We also had really large blocks, because someone dropped
               | one on my head.
        
             | ehnto wrote:
             | Exactly, having control over the artifact is so empowering
             | for learning and curiosity. A simple image or gif wouldn't
             | be nearly as engaging.
        
         | circadian wrote:
         | "This page summarizes pretty good what web technology is
         | capable of, when in the hands of a real professional."
         | 
         | I was looking at this when I went to bed, and though the
         | subject matter isn't completely new to me I was enthralled by
         | the execution and stayed up and read all of it...
         | 
         | Absolutely LOVE the way this has been put together, it really
         | speaks to me of beauty in simplicity, at least from the visual
         | perspective!
        
       | Waterluvian wrote:
       | This, like the Fourier Transform webpage, is a masterpiece.
       | 
       | Silly Question: when I add gasoline to my car it's a liquid. When
       | it enters a cylinder of my Engine, mixed with air, is it still a
       | liquid? Is it a gas? Aeresolized? What causes the change in state
       | and when/where?
        
         | [deleted]
        
         | petrocrat wrote:
         | Can you share a link to the Fourier Transform page that you
         | mentionted, please?
        
           | Waterluvian wrote:
           | https://www.jezzamon.com/fourier/
        
         | wolfgang42 wrote:
         | It's an aerosol, fine droplets of liquid in a stream of air. It
         | used to be the carburetor that added the fuel to the airstream
         | (by way of the Bernoulli principle); modern cars use a fuel
         | injector, which works on much the same principle as a spray
         | bottle to create the fuel-air mixture directly in the cylinder.
        
       | 49yearsold wrote:
       | This is unbelievably awesome! I wish I had such material and
       | teacher like Bartosz Ciechanowski when I was learning IC engine
       | during my undergrad for mechanical engineering. Thanks a million
       | to Bartosz wherever you are and whoever you are! Simply
       | wonderful! Thank you, thank you, and thank you!
        
       | [deleted]
        
       | globular-toast wrote:
       | Over the years I've learned how most parts of a car work at a
       | basic level. Engines, clutches, gearboxes, differentials etc. I
       | can't help but feel a bit sad that it might all go away within my
       | lifetime. Electric cars are essentially just a battery and a
       | motor. They're just not very interesting.
        
       | the__alchemist wrote:
       | Question from the part of the article where the piston is
       | introduced: We know what constrains the up and down positions of
       | the piston; What constrains the direction of rotation of the
       | crank?
        
         | Sharlin wrote:
         | The crank's angular momentum, which is originally derived from
         | the turning of the starter motor.
        
           | the__alchemist wrote:
           | Thank you. So the engine can go either way, and the direction
           | is determined by the initial rotation?
        
             | Sharlin wrote:
             | As far as I know, yes.
        
       | pierrec wrote:
       | Well done. According to the author's Patreon, this is his first
       | article that's "Paid for by patrons" though no details are given.
       | His Patreon is set up so that donations happen whenever he
       | publishes a new article. I guess the advantage over recurring
       | donations is that it doesn't pressure him to crank out content -
       | he can just do it on his own schedule, and donations are always
       | justified.
       | 
       | https://www.patreon.com/ciechanowski
        
       | quercusa wrote:
       | This part delights me - check the diagram just under "now
       | whenever we push on the bucket the spring will push it back in
       | place"
       | 
       | When you release the slider _it_ springs back into place.
        
       | kingsuper20 wrote:
       | It's a lot scarier when you see things going under load at speed.
       | Lots of wiggling, twisty magic, waves.
       | 
       | Smokey Yunick (blessed be his name) used to make see-through
       | timing covers, oil pans, valve covers + strobe light + some sort
       | of oscilloscope setup to watch the craziness. I think I remember
       | seeing the results for small block Chevrolet timing gears on
       | sprint car engines as the teeth wiggled more and more with rpm.
       | Cam went backwards and forwards. Ooof.
        
         | Syonyk wrote:
         | > _Smokey Yunick_
         | 
         | Oh, man. I'm not a huge NASCAR fan, but that guy. _That guy._
         | He was an absolute _master_ of  "But the rules didn't say I
         | couldn't..." and probably is responsible for half the thickness
         | of the modern rulebook on his own!
         | 
         | "What? The fuel tank capacity can't have an inflated basketball
         | in it that springs a leak during the race, leaving us with more
         | fuel capacity?"
         | 
         | "What? The fuel lines have to be a short path between the tank
         | and engine? Now, look, _nowhere in this here book_ does it say
         | I can 't stuff the frame rails with a couple hundred feet of
         | spiraled fuel line. It gets an extra gallon or two in the car?
         | _Really?_ Huh... "
         | 
         | "Nowhere in the book does it say the bodywork has to actually
         | match the size or positioning of the stock car the race car is
         | based on. I can't help it if nobody else has totally redone the
         | bodywork to improve aerodynamics... oh, OK, you're bringing
         | cardboard templates next season, got it, that trick is done."
         | 
         | The guy was an absolute master of "creative advantages that
         | weren't actually illegal at the time they were used."
        
           | mysterydip wrote:
           | He also had an infamous Fiero with a "hot vapor engine" that
           | was claimed 50+ mpg and 250hp (when the stock 4cyl made
           | ~90hp, it was the 80s after all):
           | https://www.legendarycollectorcars.com/featured-
           | vehicles/oth...
        
           | kingsuper20 wrote:
           | The aero belly of his 1968 Camaro was interesting. The SBC-
           | powered Indy car (probably the last of home-garage built
           | vehicles for that race), the time he drove a NASCAR car back
           | from an impound without the gas tank, etc.
           | 
           | Not to say that cheating didn't happen elsewhere. Check out
           | the front-end sheet metal of the Trans-Am Boss 302s. Use of
           | the headlight holes for brake ducting. The inline Autolite
           | carb. There were some good minds at Holman-Moody, Kar Kraft,
           | Bud Moore, etc.
        
           | jborichevskiy wrote:
           | > "What? The fuel tank capacity can't have an inflated
           | basketball in it that springs a leak during the race, leaving
           | us with more fuel capacity?"
           | 
           | Pardon my ignorance- what is the motivation for temporarily
           | reducing the fuel capacity in this example? And why was it
           | disallowed?
        
             | BrentOzar wrote:
             | Your fuel tank was only allowed to hold a certain amount of
             | fuel because if you had more, you could go farther between
             | pit stops, thereby covering more laps while the other
             | drivers were stopped for gas.
             | 
             | He would temporarily meet the small tank regulations during
             | inspection, but under race conditions, the ball would
             | burst, allowing for more space in the tank, which would get
             | filled up with more fuel than his competitors at the first
             | pit stop.
        
               | nemo44x wrote:
               | If you're not cheating you're not trying.
        
               | samstave wrote:
               | How was he "caught" if thats the term?
        
               | TheGallopedHigh wrote:
               | By the mere fact that the car wasn't pitting as often.
               | Car was likely inspected afterwards.
        
               | bronson wrote:
               | Most of them weren't pitting as often as they should.
        
               | Syonyk wrote:
               | I would assume that by some point, if one of his cars
               | won, the officials just took the whole thing apart to
               | find out what sort of bizarre loophole he'd found that
               | met the letter of the requirements while totally
               | violating the spirit. His antics weren't secret, even at
               | the time he was working. He was just _really good at it._
        
               | matkoniecz wrote:
               | @TwoBit
               | 
               | I guess it depends whether you accept "technically,
               | according to rules as written (...)" is a valid
               | explanation.
               | 
               | Maybe I am wrong, but in racing it seems to be.
        
               | TwoBit wrote:
               | And nobody considers that dishonest? It's cheating in the
               | spirit of the rules if not the letter of the rules.
        
               | Wxc2jjJmST9XWWL wrote:
               | Nope ; Motorsport is always drivers' skills coupled with
               | engineering ingenuity. It's always about "what can I come
               | up with, which gives me an edge, and still somehow is
               | within the rules?" I don't know anything about Nascar,
               | but the history of Formula 1 is full of such little
               | tricks as well. It's just easier to regulate "other
               | sports" than it is to regulate sports that come coupled
               | with a lot of technological involvement.
               | 
               | If sth gives you an edge for half a season until rules
               | are adjusted, that might be enough to win a championship.
               | It's a cat-and-mouse game, but it's also exciting, and
               | important for the whole thrill of it.
               | 
               | Decades past Gordon Murray designed a fan quite literally
               | sucking cars to the ground, which somehow was within
               | regulations, because no one even considered something
               | like that https://www.youtube.com/watch?v=Hb6DAmm7sZg In
               | rally driving, they would sometimes come up with fake
               | reasons for a start to be delayed, so they wouldn't have
               | to drive in the front car's dust all the time. Audi
               | entering with their 4-wheel car back in the days was only
               | possible, because they pushed for a rule change and no
               | one else really knew what was coming. Sometimes
               | manufacturers straight up "cheated" (almost, sometimes
               | for real) https://www.youtube.com/watch?v=6lo4dGTrzr8 ;
               | it's a thin line, but also what makes it exciting.
               | 
               | I would say that it's the hacker's / engineering ethos
               | almost. What can I do within the framework? Whether it's
               | building a bridge (to make it more stable while still
               | following this brash design), a road car (how can I
               | create something fun, with torque, sound, emotion, down
               | force, power, but a nice shape, and still get a road
               | legal car within environmental regulations), computer
               | games (consider
               | https://www.youtube.com/watch?v=izxXGuVL21o ; computer
               | games are full of hacks to get the most out of the
               | hardware), even legal (how can we pay almost no taxes,
               | while not being busted for tax avoidance?) ; not every
               | ingenuity is necessarily good, but it will always be cat-
               | and-mouse, that's the point of living.
               | 
               | This got meta quick ... and quite a more detailed answer
               | than I anticipated. Sorry for that, hope I gave you a
               | different perspective though.
        
               | geocrasher wrote:
               | Excellent comment. I watched the Audi/Lancier video in
               | full. Wow. Amazing stuff. Thanks for all the info!
        
               | [deleted]
        
               | samstave wrote:
               | Was watching the formula 1 series, and one team appeared
               | to fully copy the body stylings of the mercedes team, and
               | while it was technically legal, it was morally frowned on
               | and a lot of other teams were pissed off.
        
               | Syonyk wrote:
               | No. You're free to abide by a conservative interpretation
               | of the rules, it just means you'll literally never win
               | against a team with a more creative interpretation. It's
               | very much of a realm of "That which is not explicitly
               | forbidden is permitted." And the range of "explicitly
               | forbidden" tends to be based heavily on what the rules
               | body feels offers too much advantage.
               | 
               | It's quite literally a major part of what makes the sport
               | interesting. Yes, driver skill matters, but an
               | exceedingly creative crew chief (see Smokey) is worth
               | quite a bit more.
               | 
               | Some of it is certainly "cheating, good luck catching
               | us." Some of the trick throttle body restrictor plates
               | that look like a perfectly valid restrictor plate ("A
               | hole of X diameter to restrict airflow to the engine so
               | everyone has the same power") end up flowing a lot more
               | are pretty clearly cheating - they're against both the
               | letter and spirit of the rules, but you have to catch
               | them, which is hard.
               | 
               | Others? It's literally just undefined areas. To borrow a
               | few of Smokey's antics, sure, the car has to be based on
               | a stock car you can buy - but does it have to be
               | dimensionally identical, or can you get creative? He did
               | things like create smoother windshield/frame junctions to
               | reduce drag, extended the bumper down to improve
               | aerodynamics, etc. Is that cheating, or is that just
               | creative optimization within the rules? You were, at one
               | point, allowed to use an alternative frame for the car.
               | As worded, that doesn't _prohibit_ a custom made frame
               | with the drivetrain offset to one side for balance
               | improvements for circle track duty... but is that
               | actually _cheating_? It never said you couldn 't.
               | 
               | One might reasonably assume that a fuel line routing
               | would be "a more or less direct and protected path from
               | the fuel tank to the engine." But, if you've not
               | specified this, and someone stuffs the frame rails with a
               | couple gallons worth of spiraled fuel line... the
               | requirements specify _fuel tank capacity._ They don 't
               | specify _fuel line length or capacity._ So if you stuff a
               | ton of the largest diameter fuel line you can get your
               | hands on in just about every frame rail and it doesn 't
               | say you can't... well, is that cheating?
               | 
               | The rules have gotten more strict over time, but there
               | are still plenty of creative ways to use the provided
               | parts. A few years back, some team found some way to use
               | the provided suspension components, within spec, to meet
               | the ride height requirements at the start of the race,
               | when it was measured. They were _consistently_ lower than
               | they ought to be at the end of the race, but they used
               | the provided parts and met the requirements, as written,
               | at the time they were racing. I believe the letter they
               | got was essentially,  "We can't figure out what you're
               | doing, but stop it, and we're going to start checking
               | ride height at the end of the race, here's the
               | tolerances." They met every requirement provided, but
               | found some way or another to get an advantage.
               | 
               | And that's just NASCAR. You get into F1 with
               | "functionally unlimited budgets" and some of the
               | engineering insanity that is entirely within the bounds
               | of the rulebook, but is still wonderfully absurd...
               | 
               | Stuff like "You never said we had to race with the
               | physical engine we qualified with, so our qualifying
               | engine is run at the literal edge of holding together and
               | we replace it before the race." I believe it was BMW that
               | got around 1500hp out of a 1.5L motor (so 1000 HP/L), but
               | the engine more or less came apart at the end of the
               | qualifying laps.
               | 
               | Can you water cool your brakes? Well, OK, nothing against
               | it. Whoops, did you water cool your brakes so much you're
               | underweight during the race, but refill the tank before
               | post-race weigh in? Well...
               | 
               | Far as I'm concerned, this is the sort of thing that
               | makes racing interesting!
        
               | richardw wrote:
               | The same ethos added to pro cycling is pretty much
               | considered cheating but I'd guess not in the inner
               | chambers. Fair game as long as you pass the tests? Draw
               | oxygenated blood out and put it back in halfway through a
               | tour. Now that's called blood doping. Rinse and repeat,
               | for decades:
               | 
               | https://en.m.wikipedia.org/wiki/List_of_doping_cases_in_c
               | ycl...
        
               | rocqua wrote:
               | People do, that's why the rules are changed after a
               | while. Competitors are usually outraged. Fans are
               | somewhat split. Rulemakers are annoyed, but don't
               | retroactively change the rules.
        
               | jborichevskiy wrote:
               | That makes sense, thanks. Clever!
        
             | ska wrote:
             | I suspect that it increased the fuel capacity from the
             | nominal "max" at race start, so when you hit a pit stop you
             | can put more in.
        
             | [deleted]
        
             | WalterBright wrote:
             | Fuel capacities are reduced to minimize the fire in fiery
             | crashes. But lower fuel capacity means more pit stops,
             | which the racer wants to minimize.
             | 
             | Temporarily reducing fuel capacity means the car passes
             | tech inspection, but really has more capacity.
        
             | [deleted]
        
             | Syonyk wrote:
             | Fuel tank capacity is required to be 10 gallons. Say, 20
             | laps or so.
             | 
             | They check, at the tech inspection, that your tank doesn't
             | hold more than 10 gallons. Great.
             | 
             | Except, once you deflate the basketball (or get creative
             | with routing fuel lines all over the car), you _actually_
             | have 11-12 gallons onboard.
             | 
             | Which means, at the end of the race, when everyone else has
             | to pit, you can make the "risky option" to skip the final
             | pit stop, keep rolling, and, well, surprise of surprise,
             | make it over the line (in first place) before you flame
             | out.
        
               | jborichevskiy wrote:
               | Ah, that explains the fuel lines as well. Very
               | interesting!
        
             | zombielinux wrote:
             | When you qualify, your fuel tank is only allowed to hold X
             | gallons. With the basketball inside, it held X gallons.
             | 
             | When the basketball sprang a leak and deflated, the tank
             | held X+Y gallons, netting a slight advantage between pit
             | stops (an extra lap or two over 500 miles adds up)
        
             | [deleted]
        
             | jakogut wrote:
             | I assume the rule book specified a maximum fuel tank size,
             | to ensure that teams were making roughly equal pit stops
             | for refueling, etc. Installing a larger fuel tank with the
             | volume taken up by an adjustable air reservoir means the
             | tank starts at legal capacity, and increases in capacity
             | after the race begins, allowing fewer stops for refueling.
        
         | adrianpike wrote:
         | We had a see through engine w/strobe system at the uni I
         | studied vehicle engineering at, it was really really
         | educational to be able to adjust ignition timing and fuel
         | mixture and see how it would change the color & shape of the
         | flame front.
         | 
         | Probably a ton easier to simulate it these days but at the time
         | it was absolute magic and really helped me understand how to
         | ear-tune an engine to at least good enough to get on a dyno.
        
         | gooseyard wrote:
         | Kevin Cameron from Cycle World has written some of the most
         | fantastic articles about these topics, in particular there's
         | one that I'm struggling to find about the problems with solid
         | camshaft mass when rpms started to get really high and resulted
         | in cam oscillation and failure, so they were made hollow, only
         | to then discover they got too hot, which led to making the
         | sodium filled, and on and on.
         | 
         | Also a couple of great ones about the struggle to find alloys
         | for radial engine cylinders that could flex without cracking.
         | His writing is so insightful and concise!
        
         | towndrunk wrote:
         | You can get clear valve covers for some BMW motorcycles now.
         | https://www.youtube.com/watch?v=BE71lpgJ4ng
        
         | TheSpiceIsLife wrote:
         | How much of that was really metal elasticity and how much
         | artifacts of the camera technology used, eg. rolling shutter?
         | 
         | I work with metals all day every day, and damn can it flex, but
         | would have imagined the high carbon steels used in engines
         | would he fairly still.
        
         | bob1029 wrote:
         | Reciprocating machines are fairly remarkable when you consider
         | all of the components involved, forces, etc. Even more so when
         | you think about how long a typical car engine lasts.
         | 
         | These incredible forces are why rotary and turbine engines are
         | substantially more reliable. Some gas turbines have only 1
         | moving part, and in some applications this moving part
         | experiences zero wear due to magnetic/aerodynamic/active
         | bearings.
        
           | kingsuper20 wrote:
           | Rotaries are a funny case. Look good on paper. Thermal
           | efficiency issues. Smog. Seals. Noise control difficulties.
           | Weird patches like bridge ports.
           | 
           | For modern passenger cars, it's kind of like overcoming the
           | difficulties of two-stroke.
           | 
           | In anti-defense of 4-stroke ICE, it seems to me like we are
           | hitting peak wacky complexity of those. Variable timing cams,
           | turn off the cylinders, direct port injection, turbos,
           | variable intake, complicated ECU. It's a far cry from a
           | flathead 6 or VW flat 4.
           | 
           | Thank God electric cars are becoming more available, although
           | I fear increasingly complex cooling and battery management
           | and the 1000 things a software guy is going to add to them.
        
             | baybal2 wrote:
             | The problem with ICE industry is that nearly nothing
             | improves much in absolute terms.
             | 
             | If you take a look at list of ICE records, nearly all of
             | them were made decades, and decades ago.
             | 
             | Biggest piston engines - early 20th century
             | 
             | Most powerful piston engines - fourties
             | 
             | Most efficient piston engine - Jumo 204 held the record
             | until nineties
             | 
             | Most power to weight - eighties
             | 
             | Uncounted billions put into engine RnD were mostly about
             | scraping last few percents off everything above, and
             | environmental compliance.
        
               | dahart wrote:
               | > Jumo 204 held the record until nineties
               | 
               | And what has happened since then? Google is showing me
               | several engines with breakthrough efficiency in the last
               | 10 years.
               | 
               | When I was a kid in the 90s, SUVs commonly got 12 MPG.
               | The new models are 25 sometimes 30 MPG. Emissions have
               | gotten considerably better in the last 30 years.
               | 
               | I'm looking and can't find any info to back up the claim
               | that this 1920s engine was more efficient than engines
               | designed in the 80s and 90s. I am curious about it, not
               | just is it true, but specifically what kind of efficiency
               | you mean and what design features made it efficient. Do
               | you have any sources or reading? Wikipedia talks about
               | how the arrangement of the valves increased the
               | efficiency, but only says this made it approach four
               | stroke efficiency (at the time), not that it exceeded
               | other designs. The 204 was a two stroke, and it seems to
               | be common knowledge that even today, four strokes are
               | more efficient.
               | https://en.wikipedia.org/wiki/Junkers_Jumo_204
        
               | stickfigure wrote:
               | Like those distorted maps of the united states weighted
               | by population[1], your post should be read with
               | "environmental compliance" as the center of mass. Yet you
               | shrug it off like a footnote. Nobody, except perhaps ship
               | designers, cares who has the biggest piston engines.
               | 
               | [1] http://www-personal.umich.edu/~mejn/election/2016/
        
             | elihu wrote:
             | > Thank God electric cars are becoming more available,
             | although I fear increasingly complex cooling and battery
             | management and the 1000 things a software guy is going to
             | add to them.
             | 
             | I'm hoping lithium iron phosphate starts to be used more in
             | midrange vehicles; partly because they can be scaled up
             | while sidestepping the potential resource bottlenecks
             | around cobalt and nickel, and partly because they're very
             | durable and cooling isn't usually much of an issue. Though
             | heating might be an issue in the winter time (most LFP
             | cells don't like being charged when temperatures are below
             | freezing; heating might be necessary in winter).
        
           | bitexploder wrote:
           | [*] more reliable in theory. Mazda RX8 and rotary engines are
           | famous for being a bit maintenance heavy and unreliable.
           | 
           | The amount of engineering and brain power that has gone into
           | making common ICE engines in cars in wide deployment reliable
           | is staggering.
        
             | Dork1234 wrote:
             | I've own an RX8 maintenance came down to adding oil every
             | few fill ups, and changing spark plugs every 10k miles. If
             | you treat the engine correctly, the will easily get to 100k
             | miles, if you drive the engine incorrectly (run at low
             | RPM), or run low on oil things won't last long. The car is
             | a sports car and won't get you worry free 200,000 miles
             | like Accord or Camry. Even the S2000 had similar oil usage.
             | 
             | Talking to the dealers I took the car too, many of the
             | issues with related to people who didn't warm engine up, or
             | baby the engine below 3,000 rpms causing carbon build up.
        
             | bob1029 wrote:
             | Agreed on automotive rotary. It's not in the same spirit as
             | the gas turbine and others.
        
         | roflchoppa wrote:
         | i just got a driveshaft balanced for my 240z, it was 2/3oz out
         | on the front and 1/3oz out on the tail. I was thinking how much
         | force would that generate at speed.
         | 
         | Hopefully the vibration problem is gone.
        
       | tyingq wrote:
       | The quality of the explanations, and progression of complexity,
       | reminded me of an old video that explains how a car's
       | differential (rear end) works:
       | 
       | https://www.youtube.com/watch?v=yYAw79386WI
       | 
       | Skip to 3:30 for the explanatory part.
        
         | obiwanpallav1 wrote:
         | This video is a gift.
        
         | alanbernstein wrote:
         | Wow, this video was fantastic, thanks for sharing. I see how
         | the progression reminded you of this, but the physical demo
         | presents as more of a history-of-mechanisms lesson, which is
         | fascinating.
         | 
         | I also appreciated the humor. They seem to have built a working
         | mockup of a car with the driveshaft penetrating the passenger
         | compartment, just to make the joke that it would be
         | inconvenient to rest luggage on the spinning shaft.
        
           | warmwaffles wrote:
           | If you really want a rabbit hole, I suggest this guy's
           | channel.
           | https://www.youtube.com/channel/UCwosUnVH6AINmxtqkNJ3Fbg
        
       | RamRodification wrote:
       | Can we have better titles please?
        
       | ekianjo wrote:
       | What is the best way to archive such a page for offline browsing?
       | I tried ArchiveBox on this, but all the animations are gone in
       | the offline version (no matter which method was used).
        
       | soperj wrote:
       | That was awesome. I'd love to see another with the Wankel engine!
        
       | _acco wrote:
       | Animagraffs also has an amazing short on the ICE:
       | 
       | https://www.youtube.com/watch?v=ZQvfHyfgBtA
        
       | ehnto wrote:
       | Wow, that was perfectly executed. A testament to what the web can
       | be.
        
       | enono wrote:
       | HOW
        
       | xixixao wrote:
       | Open devtools, Sources, ice.js, on line 5193, change 2 to 40.
       | Fixes the speed of the first animation.
       | 
       | Disclaimer: I don't know what the real speed should be. The whole
       | website is amazing though.
        
       | npunt wrote:
       | Another great Bartosz Ciechanowski creation. Also check out his
       | past work [1] about light & shadows, cameras & lenses, color
       | spaces, floating point, etc.
       | 
       | [1] https://ciechanow.ski/archives
        
       | barcosofttech wrote:
       | hello
        
       | fideloper wrote:
       | whoops thought this was an article about basecamp
        
       | iaw wrote:
       | I spent a couple years trying to fully understand automotive
       | systems tip to tail and did pretty well (excluding transmissions,
       | they're magic). This is _the best_ illustration of how engines
       | work that I 've ever seen.
        
       | mrfusion wrote:
       | Isn't it risky for the timing to rely on a rubber belt? Does it
       | never slip? Even a mm of slippage seems like it would make the
       | valve timing stop matching the pistons?
        
         | frosted-flakes wrote:
         | Timing belts are toothed, and if installed correctly they will
         | never slip. Modern kevlar timing belts are near-indestructible
         | under normal use. The real problem is the pulleys--once those
         | bearings wear out, they can seize, causing the belt to slip or
         | even break.
        
         | pjc50 wrote:
         | Timing belts have teeth.
         | 
         | Occasionally chains are used instead; more expensive and
         | heavier, but more durable. You do need to maintain the timing
         | either way it it will destroy the valves.
        
           | elihu wrote:
           | I think another reason belts are common is that chains tend
           | to be a bit noisier.
        
           | bluedino wrote:
           | If the engine is a non-interference design, losing the belt
           | won't be catastrophic for the valves
        
           | thereisnospork wrote:
           | >Timing belts have teeth.
           | 
           | To expand: It is the teeth that make belts timing belts, they
           | keep the 'timing' (relative rotational orientation) of 2 or
           | more toothed pulleys. In an ICE the camshafts are locked to a
           | 2:1 ratio to the crank shaft, in a 3d printer it keeps an
           | axis fixed relative to the stepper motor shaft.
        
         | blamazon wrote:
         | In addition to what frosted-flakes said, many engines are "non
         | interference" design so that if the belt snaps or jumps a tooth
         | the engine won't be destroyed, and the belt will just need to
         | be replaced. However, non interference engines are not as
         | compact as interference engines.
         | 
         | Many engines also use a timing chain instead of a timing belt,
         | but this carries extra weight and requires lubrication.
         | 
         | It's all about tradeoffs!
        
           | TheSpiceIsLife wrote:
           | The engine in one of the vehicles I own has timing _gears_
           | rather than a chain or belt. Another option, different trade-
           | offs.
        
             | CRConrad wrote:
             | Much more common with pushrod engines, where the camshaft
             | is situated close to the crankshaft; less so with overhead
             | camshafts. Though I think some very high-revving sports and
             | competition engines have gears driving overhead cams; IIRC
             | the McLaren TAG F1 turbo V6 (by Porsche) back in the 1980s
             | was one example.
        
               | blamazon wrote:
               | The engine used in the Ferrari Enzo and Maserati MC12 is
               | a notable example:
               | 
               | https://36.media.tumblr.com/8a928fcccf1b41e82be0273ccbe20
               | 05a...
        
           | [deleted]
        
         | lubesGordi wrote:
         | It is risky and they do slip or even break from time to time.
         | They are generally a 100k maintenance item. The alternative is
         | a chain, which can also fail (or other related components), but
         | is generally not considered a maintenance item.
        
         | mxxx wrote:
         | Yeah it's one of those things that you just have to replace
         | every X miles just to be safe. I got one replaced a couple of
         | days ago because the service history was missing and I couldn't
         | tell whether it had ever been done. If your timing belt goes
         | you're in all sorts of trouble.
        
           | mulmen wrote:
           | When I started driving German cars (may be coincidental) I
           | noticed my mechanics would write the date and miles of the
           | service directly on the parts.
           | 
           | My Toyota actually had a small decal on the timing belt cover
           | itself specifically for the purpose of tracking that service.
        
         | MAGZine wrote:
         | The belts are finely machined to very small tolerances, and
         | things are tightened to specific foot-pound tolerances to make
         | sure they sit exactly where they need to. So no, nothing slips.
         | 
         | I just went through a belt change with my brother not long ago.
         | The tolerances you're dealing with are measured in thousandths
         | of inches. Something that wasn't installed quite straight can
         | cause almost imperceptible wobble that can destroy things under
         | load.
         | 
         | Still, every day shop tools will help you get the precision you
         | need.
        
         | mulmen wrote:
         | My first car would diesel after turning it off. Basically the
         | engine would keep running on fuel in the carburetor and
         | residual heat in the engine. Sometimes it would do this
         | _backwards_. This was very problematic because the timing belt
         | tensioner only worked in one direction. When it ran backwards
         | the timing belt would jump a tooth then the car would not
         | start. I got in the habit of just killing the motor with my
         | foot on the brake and the car in gear then letting the clutch
         | out.
         | 
         | I also had the machine shop at my high school weld up a custom
         | tool to help me reset the timing belt in a parking lot with a
         | couple of hand tools. It could be done in a few minutes.
         | 
         | This is a long way of saying yes, if they slip it is bad.
        
         | arh68 wrote:
         | Rubber with embedded steel wire is less stretchy than the
         | rubber bands we're used to. Tires even more so than belts; it
         | adds integrity like rebar in concrete.
         | 
         | You're correct that once it jumps even 0.5cm (~1 tooth) it
         | could touch piston to valve; it depends on the engine, but I'd
         | wager most nowadays are interference.
        
       | csbartus wrote:
       | This post has 1199 points and 290 comments, a 4:1 ratio.
       | 
       | This always rings me an alarm: Hey, this is something
       | extraordinary even Hacker News can't deal with it (via the usual
       | way, like on posts with an inverse points/comments ratio,
       | indicating hate and flame inside).
       | 
       | Right, this guy is a genius.
       | 
       | Together with Amelia Wattenberger they represent a new wave in
       | storytelling: Meaningful content and meaningful interactions.
       | 
       | The previous wave was proven to be a bubble. Embraced, supported
       | and pushed by mainstream media (NYTimes, Bloomberg, Spotify) the
       | formula for the first wave was not successful: Meaningless
       | (average) content + Meaningless (flashy, art-pour-art, attention-
       | seeking, etc) interaction.
        
       | toxik wrote:
       | This was excellent, but should perhaps be clarified that this is
       | a gasoline engine - diesels don't ignite by spark, but by immense
       | pressure in the chamber. This also invalidates the "you cannot
       | add fuel to increase power" of gasoline engines. Diesels can (and
       | should!) run at lower rpm; they don't stall because the ECU can
       | add fuel to increase power output.
        
         | keanebean86 wrote:
         | What I want to try is replacing valves with electric iris
         | mechanisms. The computer would signal the iris to open or close
         | depending on the situation.
         | 
         | No more complicated variable valve stuff. Just hold the iris
         | open longer. Also no more interference engines and timing
         | chain/belt changes.
         | 
         | Iris:
         | https://commons.m.wikimedia.org/wiki/File:Iris_Diaphragm.gif
         | 
         | Edit: fixed typo, added link to iris gif
        
           | toxik wrote:
           | It's a good question, why is only fuel injection and ignition
           | computer controlled? The intake and exhaust valves must also
           | be solenoid controllable.
        
             | opwieurposiu wrote:
             | This exists, but it is very expensive.
             | https://www.freevalve.com/freevalve-technology/
        
             | LeonM wrote:
             | Swedish hypercar builder Koenigsegg has made a system like
             | this, they call it FreeValve.
             | 
             | Their upcoming car called the Gemera will feature
             | FreeValve, its 2.0L 4-cylinder is said to generate over
             | 600HP. Though it must be said that this is a 1.5 million
             | dollar car, so don't expect this kind of performance per
             | displacement from other brands.
             | 
             | A guy on Youtube made his own version of freevalve, and got
             | it to work on a Mazda Miata:
             | https://www.youtube.com/watch?v=E9KJ_f7REGw
        
             | golemiprague wrote:
             | Because of reliability and the potential damage, not
             | injecting fuel is not such a big deal but a stucked valve
             | can cause serious damage with all the pressure inside the
             | cylinder. There are some cars now with no camshaft, but
             | they are very high end experimental sport cars like
             | Koenigsegg
        
           | addison-lee wrote:
           | I don't think an iris like that would last very long with the
           | immense pressures in the cylinders. It makes way more sense
           | to electronically control the valves themselves, like
           | Koenigsegg is doing with their Freevalve tech, so you get the
           | mechanical seal of the valve with the control of electronics.
        
             | keanebean86 wrote:
             | I figured it was something like that. It would still be a
             | fun experiment with a small engine.
        
         | Severian wrote:
         | And thus the reason why there's such as thing as a runaway
         | diesel engine.
        
       ___________________________________________________________________
       (page generated 2021-05-01 23:01 UTC)