dieziege wrote:
The reason that is true is that the air is about 79% as dense as "standard" air.
That's point one... now we get to the mixture being off. Ideal mixture is around 14.7:1 air:fuel mixture. In other words, for every 14.7 pounds of air one pound (sixth of a gallon roughly) of gas is added. That's what your carb is set up for (approximately). Now, this is simplistic... but if we assume an ideal mixture at sea level and an 80% density at our actual altitude, the mixture is going to be roughly 11.7:1 (this is wrong, but it isn't as wrong as it could be).
Ok, not to get into any kind of a science lecture, but I am a little confused as to why your carb is set up to use X amount of
pounds of air and gas. I would think that it would measure a certain "volume per unit time" and not weight. Simply because you can adjust airflow and gas flow into an engine with a nozzle. This is why you would have problems with the denisty of the air at higher altitudes or with higher humidity. The same volume of gas is going into your engine, but there is more moisture in the mixture so you are getting less O2 and N2 which gives you a weaker "BANG."

Why is it measured in weight? You seem to know alot about this stuff, maybe you can help me figure this out. Thanks.
(Not trying to be pretentious or anything. Just an Aero Engineering kid who gets off on this stuff.

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