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How a Car Engine Works

jacoboneal.com

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Re: How a Car Engine Works

#84
post #75
post #42

Hi fellow gear-heads... very cool engine graphics! On a related note, I wanted to add that, if you are not familiar with dual-clutch transmissions [1], they are pretty interesting. One example (many manufacturers offer this type of transmission) is the Porsche Doppelkupplungsgetriebe (or simply PDK) [2], developed by Porsche. It is essentially two gearboxes in one complete transmission package, where both gearboxes p…

That's one of the major reasons the GT-R is so quick off the line and down the quarter mile. It was the first production car with a dual-clutch transmission that was actually realistically priced, and it's still arguably the most cost-effective.

Actually VW sold a dual clutch DSG transmission in the 2003 R32, years before the GTR hit the market, and for a fraction of the price. All other things the same, a dual clutch is not much faster than a properly-operated manually-clutched gearbox, but in the case of the GTR, we'll never be able to make that comparison.

Re: How a Car Engine Works

#85
post #29

Water boil at exactly 100 degrees Celsius... not the conversion of 212 degrees Fahrenheit. Americans. ;-) Nice job still.

If you're going to take it that far you have to add "at standard pressure".

Also, I was under the impression that coolant does not boil at that high a temperature at standard pressure. The point of the sealed coolant system is to increase the pressure and hence the boiling point, but if it boiled at that temperature by default that would be unnecessary since no engine runs that hot.

Re: How a Car Engine Works

#86

Since we've got a bunch of awesome gearheads commenting, can someone tell me why manual transmission is so easy to stall out? Particularly between say 1st and 2nd (although I'm sure it's got nothing to do with the actual gears). Just curious. ...aside from obvious commentary of my abilities driving manual ;)

> Since we've got a bunch of awesome gearheads commenting, can someone tell me why manual transmission is so easy to stall out? Particularly between say 1st and 2nd (...)

It's not easy, only if use it wrong. It's easy to stall going from neutral to 1st if you don't apply enough gas (for instance, if you're on a slope, or the car is loaded), but it will only stall from 1st to 2nd if you're trying to do it from too low RPM (in this case the engine may take a while to stall completely, you can still avoid it by unclutching), or if you work the clutch too fast (the engine stalls right away).

Re: How a Car Engine Works

#87

This is a great illustration that demonstrates why gasoline engines NEED to die and be replaced by better, more efficient engines.

The problem isn't the efficiency of the engine, but the efficiency of storing energy. Gasoline and diesel are very good at that, and are easily replenished. If your concern is the complexity of all the moving parts, rotary engines and 2-stroke engines are significantly simpler, but ultimately 4 stroke reciprocating engines make more sense.

Re: How a Car Engine Works

#88

Since we've got a bunch of awesome gearheads commenting, can someone tell me why manual transmission is so easy to stall out? Particularly between say 1st and 2nd (although I'm sure it's got nothing to do with the actual gears). Just curious. ...aside from obvious commentary of my abilities driving manual ;)

You might look at what RPM you are shifting from 1->2. As the other poster said, 1->2 stalls are uncommon because the vehicle is in motion and the power from the forward inertia coming up the drive train into the engine is frequently enough to spin the motor, even if its shut off. However, if you upshift too soon, the engine with the 2nd gear ratios will be spun too slowly for the engine to pull itself out, and will instead drag the car to a stop.

Re: How a Car Engine Works

#89
this is really cool. would love to see one breaking-down wankel engines as well.

though i'm not technical by any means, i've always sort of got the high-level around how reciprocating/piston-based engines function. wankel engines seem a lot more efficient in terms of design but also weirdly complex. still kind of a mystery to me as to how they work and unfortunately there aren't too many cars around these days that run on em to check out..

Re: How a Car Engine Works

#90
post #55
post #43

Earlier quoted context omitted.

Well they both work on compression, diesels simply rely on it more than gasoline engines. Diesel engines work on what's called adiabatic compression heating. In other words, the compression causes the air to heat to a point higher than the ignition point of the fuel. Diesel engines usually use glow plugs to compensate for the lack of adiabatic compression heating when the engine is cold.

See also the awesome fire piston, a relatively ancient technology using the same principles: https://en.wikipedia.org/wiki/Fire_piston

The inventor of the diesel engine based his design on the fire piston technology.
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