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Internal Combustion Engine

ciechanow.ski

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Re: Internal Combustion Engine

#71

Post by zombielinux »

jborichevskiy wrote: post #57
Syonyk wrote: post #36

Earlier quoted context omitted.

> 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 pat…

> "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?

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)

Re: Internal Combustion Engine

#72

Post by [deleted] »

jborichevskiy wrote: post #57
Syonyk wrote: post #36

Earlier quoted context omitted.

> 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 pat…

> "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?

[deleted]

Re: Internal Combustion Engine

#73

Post by [deleted] »

csours wrote: post #50

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]

Re: Internal Combustion Engine

#74

Post by kingsuper20 »

dahfizz wrote: post #59
kingsuper20 wrote: post #56

Earlier quoted context omitted.

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.

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.

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.

Re: Internal Combustion Engine

#75

Post by jborichevskiy »

BrentOzar wrote: post #61
jborichevskiy wrote: post #57

Earlier quoted context omitted.

> "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?

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…

That makes sense, thanks. Clever!

Re: Internal Combustion Engine

#76

Post by jborichevskiy »

Syonyk wrote: post #70
jborichevskiy wrote: post #57

Earlier quoted context omitted.

> "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?

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…

Ah, that explains the fuel lines as well. Very interesting!

Re: Internal Combustion Engine

#77

Post by the_cat_kittles »

elihu wrote: post #47
specialp wrote: post #15

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 in…

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…

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!

Re: Internal Combustion Engine

#78

Post by jakogut »

jborichevskiy wrote: post #57
Syonyk wrote: post #36

Earlier quoted context omitted.

> 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 pat…

> "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?

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.

Re: Internal Combustion Engine

#79

Post by toxik »

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.

Re: Internal Combustion Engine

#80

Post by gooseyard »

kingsuper20 wrote: post #10

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.…

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!

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