That was me who asked. Now that I
have my fuel system mostly plumbed you tell me this! Oh well, in a few
years I’ll let you know how my two EFI pumps do against my facet.
Ron Milligan
RV7 QB Fuse
Aliso Viejo CA
From: Rotary motors in
aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of Russell Duffy
Sent: Sunday, November 21, 2004
7:00 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: inflight
fuel transfer (was Re: how do you carry, and measure oil?)
Speaking of fuel transfer, my system is
like Tracy's,
in that I feed from only one tank, and use the other to transfer to the
feed tank. The transfer pump is a lowly Facet 5-6 psi pump. The
feed tank has two high pressure EFI pumps, and one AN-6 return line from the
regulator. My transfer pump Tees into the return line from the
regulator.
A while back, someone asked if the return
from the regulator would overpower the Facet pump, and keep fuel from being
transferred to the feed tank. The answer is that it can be a problem if
you're running both EFI pumps. My normal flight mode is to run both EFI
pumps at all times. I test them individually on pre-flight, and
would turn one off if I lost an alternator, but normally, they stay on. I
found that this causes so much flow in the return line that it does overpower
the Facet pump. I bet I could leave the Facet on all the
time, and it MIGHT transfer enough to make up for what I burn. In other words, the transfer is very
slow. Turning off one of the EFI pumps improves this considerably.
If I were doing this over, I'd have separate fittings for return fuel from the
regulator, and for transfer fuel from the non-feed tank.
Rusty (fresh out of comments)