On Tue, 20 Jan 2009 08:30:34 -0800 (PST),
wrote:

On Jan 20, 6:32 am, Stealth Pilot
wrote:

as for the changes in velocity or density actually changing the fuel
flow well hmmmmm. if an engine can be run from sea level to about
6,000ft at full rich and still run and produce power, well that doesnt
seem like too much of a flow change with density.

Combustible mixtures range from 8:1 (air:fuel by weight) to
18:1. At sea level at full rich it'll be around 10:1. Pretty rich. As
you climb it'll head for 8:1 as the air's density decreases and the
engine will start to run rough and make black smoke. The mixture is
changing and you need to do something about it. We have airplanes here
at 3000' ASL that won't run nicely at all at full rich on a standard
day and we have to lean them for takeoff if it's any warmer than that.

Dan

thanks for the mix ranges dan. couldnt recall them.
do you have an answer for the guy's original question?