Recent content by 84Turbo

Your formula is comparing apples to oranges. Carburetors are rated at a pressure drop (1.5" Hg, IIRC) (not a mathematical formula with assumptions as in the engine example). Pressure drops in the intake reduce power. There's a reason Grumpy Jenkins used to run a pair of 660's on his 331" SBC...

We are finally in agreement! Some people will do what they want, despite the fact it doesn't make any technical sense.

You're spot on! :thumb

Because it can't create additional power. An internal combustion engine is an air pump. You make power by injesting (and eventually expelling) the maximum amount of air (and yes, fuel, but fuel is not the difficult part to increase in an engine). Backpressure reduces the mount of fresh air that...

On the contrary, I will be happy with any answer that obeys the laws of physics.

I'm not trying to be rude here, but you have a serious lack of understanding of how an engine works, not only in the mechanical details, but the gas flow dynamics. Please, for your good, and my sanity, get a textbook on internal combustion engines and do some reading.

We are in agreement that there are a lot of myths out there (needing backpressure, for one). But, back to your statements. You are mistaking the effects of reversion (reverse flow into the intake manifold) and its effect on A/F ratio in carb'd engines, and backpressure. These are two...

I'm not sure I understand your balance statement. I am in disagreement with some previous posters who state that backpressure is beneficial to engine performance. I still say it is not, and I am still waiting for any examples to show where it is beneficial.

Your highlighted (bold) sentences support my position. You cannot have good scavenging if the exhaust stream slows down quickly due to the backpressure encountered when gas is forced to travel through a restrictive path.

Because bigger engines have to expel a greater mass of exhaust gas than a small engine does, and it's frequently called upon to do this task in the same amount of time as the smaller engine. Trying to push a lot of stuff through a small hole (pipe) takes more effort/pressure at the pressurehead...

Can you quote any law of physics that would support this?

Can you show me any examples, or any laws of physics supporting your position?

Yes, there are too many. And several of them are in your first paragraph.;) Cooling is not necessarily bad in all cases. When a gas cools (in a contained volume), the pressure drops. Reduced backpressure is a good thing. Regarding the dreaded change in density, the mass content of the exhaust...

Yes, and that amount would be ZERO!