aircraft parts. This system does mandate TO and initial
operation on
that tank until enough fuel has been burned down to deal with the
pax possible return flow from another tank. This was used on (at
least)
older Bonanzas, and works just fine. No transfer pump is
required,
just a bit of care in fuel managment.
SNIP<
I'd be very careful with this approach. The return flow rate is MUCH
higher
with EFI than the mechanical A/C engine stuff. Return fuel flow in
my
installation runs from 15 to 30 GPH. Do the math and you will see
that fuel
management will be a bigger pain than installing a transfer pump.
Tracy Crook
Bill Freeman wrote:
YIKES! Why in the world is the excess (return flow) up to nearly
three
times the fuel flow necessary to produce 150 HP?? Seems like the
fuel pump puts out about 4 times the necessary flow rate. Certainly
excess
capacity is a good thing, but is there such a thing as too much of a
good thing? With this level of return fuel, I would agree that the
Bonanza
design is not a good idea. The Bonanza only needs to be run about
an hour on the initial tank (IIRC) to avoid venting fuel overboard. The
Andair dual selector seems the safest with this fuel pump size.
Is this excess flow rate planned or just how it works out with an
available pump?
Bill
I think it is for super rich full throttle acceleration Bill. Still sounds
a bit much. Tracy has mentioned 20 GPH full power full rich fuel burn
rate.
Paul Lamar
Tracy wrote:
Yes, about 20 GPH max. The high flow rate of the pump is just normal
automotive practice. Guideline is to have 150 - 200% of max flow. This is
mainly to ensure good pressure regulation. If you only had 100%, pressure
would go unstable at high flow. We once discussed strategies for reducing
pump flow at lower power settings but I would not recommend this.
Tracy Crook
tcrook@rotaryaviation.com
www.rotaryaviation.com
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