Haynes sells an excellent Build Your Own Internal Combustion Engine model, which teaches children about all of these concepts.
Internal Combustion Engine
131–140 of 415 posts
Re: Internal Combustion Engine
#132This 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.
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
It’s a good question, why is only fuel injection and ignition computer controlled? The intake and exhaust valves must also be solenoid controllable.
Re: Internal Combustion Engine
#133Earlier quoted context omitted.
> 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 dischar…
> 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…
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Re: Internal Combustion Engine
#134Re: Internal Combustion Engine
#135I 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 in…
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.
Re: Internal Combustion Engine
#136Earlier quoted context omitted.
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…
> 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, an…
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.
Re: Internal Combustion Engine
#137I 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 in…
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."
Re: Internal Combustion Engine
#138Earlier quoted context omitted.
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.…
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 machinis…
Texas Speed or TKM are two places I’d use if I were doing an LS build.
Re: Internal Combustion Engine
#139Earlier quoted context omitted.
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.
Note to replace copper wiring with aluminum, you have to go up at least one gauge size.
Or raise the voltage at the same time you change from Cu to Al.
Re: Internal Combustion Engine
#140Earlier quoted context omitted.
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 competito…
How was he "caught" if thats the term?
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.