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How a Car Engine Works

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Re: How a Car Engine Works

#151

Post by ams6110 »

jotm wrote: post #148
sitharus wrote: post #4

It's worth noting that the engine illustrated is a gasoline direct injection engine, which are fairly common on new cars but historically not so. Until the early 2000s most fuel injected gasoline engines were multi-point injection - the fuel was injected in to the incoming air stream immediately before the cylinder, and before that indirect injection which injected where the carburettor was. Then there are carburetto…

Ah, carburetors - how I hated those things. Simple in theory, yet so complicated and fickle in practice... I do love old diesel engines with mechanical belt-driven high pressure pumps and mechanical injectors - those things were easy to fix and built to last...

I drive a 30 year old Mercedes diesel as my primary car and it still runs like a swiss watch. You do have to adjust the valve clearance every so often, which is not necessary in a modern diesel or even ones slightly newer than mine.

Re: How a Car Engine Works

#153

Post by ams6110 »

elnate wrote: post #14
sitharus wrote: post #4

It's worth noting that the engine illustrated is a gasoline direct injection engine, which are fairly common on new cars but historically not so. Until the early 2000s most fuel injected gasoline engines were multi-point injection - the fuel was injected in to the incoming air stream immediately before the cylinder, and before that indirect injection which injected where the carburettor was. Then there are carburetto…

The other difference is Diesel engines ignite the fuel by compressing it rather than with a spark. (Also Diesel is the engine type not the fuel http://en.wikipedia.org/wiki/Diesel_engine )

yep the original diesel engine was designed to run on coal dust, unlike the modern light fuel oil diesels (kerosene, jet-A, home heating oil, and diesel fuel are all very close to the same thing, differing mainly in additives).

Re: How a Car Engine Works

#154

Post by a8da6b0c91d »

ams6110 wrote: post #151
jotm wrote: post #148

Earlier quoted context omitted.

Ah, carburetors - how I hated those things. Simple in theory, yet so complicated and fickle in practice... I do love old diesel engines with mechanical belt-driven high pressure pumps and mechanical injectors - those things were easy to fix and built to last...

I drive a 30 year old Mercedes diesel as my primary car and it still runs like a swiss watch. You do have to adjust the valve clearance every so often, which is not necessary in a modern diesel or even ones slightly newer than mine.

I drive a seven year old motorcycle and carburetors + ethanol = nightmare. A tank of gas with the ethanol admixture will often go bad enough to gum up the carbs in just a few weeks. I've had the engine stall out under me in potentially dangerous situations twice because of this. Damn corn farmer lobby.

Re: How a Car Engine Works

#155

Post by sigkill »

grecy wrote: post #103
nexox wrote: post #100

Earlier quoted context omitted.

You seem to have ignored my "All other things the same" qualifier - that means you have to assume that power, weight (except for the difference between the gearboxes,) suspension, environment, tires, and everything else, is identical for the quoted part of my sentence to apply. I don't see how your first two points are relevant to what I said, or your original post. You can love the GTR all you want, I don't mind, an…

> I don't see how your first two points are relevant to what I said They're not, I just wanted to include them for the curious. > You can love the GTR all you want, I don't mind, and I never claimed that there was anything wrong with it. It's an amazing car, but it's not like I have one or even want one. >As for point 3, if you were to compare to a theoretical manual transmission GTR, that half a second of extra powe…

> with a sound system, air conditioning and creature comforts

Reminds me of that episode with May saying something on the lines of "We're going at 400kmph... and we've got air-conditioning and radio". Now, that is serious engineering.

Re: How a Car Engine Works

#156

Post by coldpie »

MrFoof wrote: post #139
nexox wrote: post #84

Earlier quoted context omitted.

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.

>All other things the same, a dual clutch is not much faster than a properly-operated manually-clutched gearbox Formula One drivers in the early 90s were the only ones really able to come close, with shift times between 150 and 200ms. The average person is more around 300 - 400ms when shifting aggressively. You can be faster than 300 - 400ms, but not with 100% consistency, especially on downshifts, and especially wit…

I'm a little surprised. I figure most people buying a Cayman S are buying it for fun. I've never driven with a DCT, but most people who have that I've heard from generally say that manual is more fun, while DCT is better in every other respect.

Did you find DCT to be at least as fun as manual? I think I'd miss the feeling of nailing the revs perfectly on a downshift while braking for a turn on the track.

Any thoughts?

Re: How a Car Engine Works

#157

Post by coldpie »

TomEllis wrote: post #133
philsnow wrote: post #131

Earlier quoted context omitted.

Right... shoes? I haven't driven a stick regularly since high school, don't people rev match with their ears ?

Yes right shoes. If you want to heel toe, you can't do it in your steel capped boots http://www.youtube.com/watch?v=muxVLOaw2ik

Eh, you can revmatch without heel-toeing. I did it for years before I started driving at the track and learned how to heel-toe. You just brake enough for the turn, then let off the brake entirely and blip the throttle and drop the clutch while turning.

Re: How a Car Engine Works

#158

Post by 001sky »

coldpie wrote: post #156
MrFoof wrote: post #139

Earlier quoted context omitted.

>All other things the same, a dual clutch is not much faster than a properly-operated manually-clutched gearbox Formula One drivers in the early 90s were the only ones really able to come close, with shift times between 150 and 200ms. The average person is more around 300 - 400ms when shifting aggressively. You can be faster than 300 - 400ms, but not with 100% consistency, especially on downshifts, and especially wit…

I'm a little surprised. I figure most people buying a Cayman S are buying it for fun. I've never driven with a DCT, but most people who have that I've heard from generally say that manual is more fun, while DCT is better in every other respect. Did you find DCT to be at least as fun as manual? I think I'd miss the feeling of nailing the revs perfectly on a downshift while braking for a turn on the track. Any thoughts…

The cayman/s has very high limits that you wont reach on a public road. If you are driving it solely on public roads, the PDK is actually great. Its good in stop and go traffic, making that occasional/daily commute to the office much more pleasant.

Re: How a Car Engine Works

#159

Post by walshemj »

Pitarou wrote: post #138

Am I the only one who sees all that complexity and yearns for a Tesla? (3 moving parts.)

Which is the same number of moving parts as a basic two stroke engine.

The trouble is the damn heavy and slow to charge batteries plus of course the environmental efects of mining all the battery materials.

What we need is a fuel cell based car with electric drive.

Re: How a Car Engine Works

#160

Post by allworknoplay »

X-Istence wrote: post #73
allworknoplay wrote: post #62

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 ;)

The only time I have stalled out is when I am pulling away in first and let the clutch come up to fast. If you are stalling your engine going from 1st to 2nd you are doing something wrong, since the wheels are moving at that point. Even if you let the clutch come up too fast the engine won't stall because the wheels will keep turning it. It might shudder and definitely not like the low RPM's, but it shouldn't stall.…

Ack, yes, you're right, I meant starting up, rather than from 1st to 2nd. I've driven a manual exactly twice roughly 15 years ago when I was getting my license; it was more of an abstract question regarding engine workings than a specific question about how to avoid stalling :)
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