Remember that the return line is positioned after the last pump
and before the mixture control valve so that the mixtrue control actually
controls the mixture (and pressure) actually reaching the
spider. If I had such a return line on my Lycoming, it would not
affect my flow sensor as it is located between the throttle body (after mixture
control) and the spider. In the Skymaster, fuel pressure,
measured from the Gage port at the spider, was displayed as fuel
flow.
Scott Krueger
AKA Grayhawk
Sky2high@aol.com
II-P N92EX IO320 Aurora, IL
(KARR)
"...as we know, there are known knowns; there are things we know
we know. We also know there are known unknowns; that is to say we know there are
some things we do not know. But there are also unknown unknowns - the ones we
don't know we don't know." D. Rumsfeld