[HN Gopher] Internal Combustion Engine
___________________________________________________________________
Internal Combustion Engine
Author : algui91
Score : 519 points
Date : 2021-04-30 09:15 UTC (13 hours ago)
(HTM) web link (ciechanow.ski)
(TXT) w3m dump (ciechanow.ski)
| engineer_22 wrote:
| What a great website, awesome animations, and intuitive
| interactives
| 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.
| 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
| 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.
| 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.
| senbarryobama wrote:
| Who did the 3D graphics for this post?
|
| EDIT:
| https://twitter.com/BCiechanowski/status/1387827101294686210
| 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.
| mgarfias wrote:
| ok, and?
| 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.
| yashksagar wrote:
| great find - i love the one on Cameras and Lenses too, great use
| of interactivity for pedagogy
| noveltyaccount wrote:
| This is incredible. I remember the Gears example from the same
| site, but now with 3D renderings. Great work.
| 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
| 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
| zmanji wrote:
| aaaaaa
| 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.
| 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.
| 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...
| 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
| 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".
| 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.
| 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.
| 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.
| 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
| 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.
| 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?
| 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.
| 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
| ;)
| 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?
| 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.
| 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.
| 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/
| 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!
| [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.
| 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
| 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."
| 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.
| 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.
| 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.
| 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.
| 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.
| 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
| fideloper wrote:
| whoops thought this was an article about basecamp
| 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
| Severian wrote:
| And thus the reason why there's such as thing as a runaway
| diesel engine.
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