Internal combustion engine.

[MITCHAY]

The long and short of it is you want advance timing. Retard is bad mmkay

[marty351]

Octane and I.Q. have a lot in common.
The lower the number, the more retarded it is.

[Crazy Dazz]

Originally Posted by daryle

Seems that all that initial energy is wasted because the piston is very close to being in a vertical position, be interesting to know when the expanding gas looses it's effective power value. Thinking maybe 1/2 way down/45%?

What you're saying makes literally no sense.

[daryle]

Air/fuel is ignited at the top of the piston stroke correct?
So at that point only a very small percentage of the power generated can be imparted to the crankshaft correct?
Then as the piston starts it's downward journey it is relying on the ever expanding air/fuel mix to impart power to the piston, is this correct?
Then my question is "when does that air/fuel expansion stop?"
If that makes no literal sense then so be it.

[b0son]

Originally Posted by daryle

Then my question is "when does that air/fuel expansion stop?"

at the bottom of the stroke. the air/fuel mixture when ignited, produces far more gas than the volume of the cylinder.

[Vesper Martini]

Originally Posted by daryle

Air/fuel is ignited at the top of the piston stroke correct?
So at that point only a very small percentage of the power generated can be imparted to the crankshaft correct?
Then as the piston starts it's downward journey it is relying on the ever expanding air/fuel mix to impart power to the piston, is this correct?
Then my question is "when does that air/fuel expansion stop?"
If that makes no literal sense then so be it.

did you watch the video in my post?

[yearby]

Originally Posted by Bevsta007

did you watch the video in my post?

Well mate I watched the video you posted. Yes I like the idea of running hydrogen and I liked the idea of being hybrid.

But using a rotary makes no sense at all. Rotary engines have a high combustion chamber surface area compared to a piston style engine, this creates a high mass of unburnt fuel in the combustion chamber causing these engines to use excessive fuel.

[yearby]

Originally Posted by b0son

at the bottom of the stroke. the air/fuel mixture when ignited, produces far more gas than the volume of the cylinder.

100% correct. The volume created by the burning gas (on the power stroke) in the cylinder exceeds the volume of the piston/cylinder at BDC. The excess volume of gas is then lost to the atmosphere via the exhaust. If this lost volume of burnt gas was used to do work, instead of heating the exhaust system the engine will become more efficient.

[Vesper Martini]

Originally Posted by yearby

Well mate I watched the video you posted. Yes I like the idea of running hydrogen and I liked the idea of being hybrid.

But using a rotary makes no sense at all. Rotary engines have a high combustion chamber surface area compared to a piston style engine, this creates a high mass of unburnt fuel in the combustion chamber causing these engines to use excessive fuel.

Not that post. see post #11

[daryle]

Originally Posted by Bevsta007

did you watch the video in my post?

Finally did watch it. Actually explained everything, even why timing is set BTDC which has always confused me.
Amazing what some guys get up to.

[Vesper Martini]

Originally Posted by yearby

If this lost volume of burnt gas was used to do work, instead of heating the exhaust system the engine will become more efficient.

You mean like bolting a turbo on to to use that exhaust flow..

[yearby]

Originally Posted by Bevsta007

You mean like bolting a turbo on to to use that exhaust flow..

Sort of, maybe, err no. On a diesel engine where increased air flow results in increased mass in the combustion chamber yes. But on a petrol engine most people would use it to increase boost and then add more fuel, and then detonation would set in, then they would lower the compression ratio to suit. The result is a massive increase in power, but a drop in efficiency, that is more fuel per HP produced.

I am thinking more HP produced per pound of fuel used.

For example- A typical petrol engine would have, let's say a 10:1 compression ratio, that is the fuel mix it compressed 10 times, and the burnt gas expands 10 times.

Now explore the idea that the engine has a compression ratio of 10:1, but an expansion ratio of 12:1.

In this case the fuel/air mixture is compressed the same amount, it burns the same, does not enter detonation just the same.
But now the burnt gases are allowed to expand another 20%, this extra expansion pushes on the piston for another 20%.

What we have now is same amount of fuel used, but burnt gas pressure on the piston for a longer period of time.

The net result is more power for the same amount of fuel used.

[yearby]

Originally Posted by Bevsta007

Not that post. see post #11

Okay, now I got you, I saw that video some time ago, found a lot of evidence for some of my theory's about engines in it.