Why not skip the pumps
altogether? My 320 was built with a parallel system. It had the
standard Facet pump set-up with the pumps in the wheel wells, clear tubing
exposed on the panel to show flow, pumping into the header. It also has
3/8 lines direct from the wing tanks to a 3-way (plus OFF) valve, where you can
select either wing tank or the header to feed the fuel pump(s). When I
first started flying the plane I used the transfer system; it was a pain in the
butt to manage (all manual). Then I started using the direct feed
system. I take-off and land on the header, but cruise pulling directly
from the wing tanks. I switch tanks every 30 minutes using my programmable
panel-mounted digital chronometer (http://www.buy-ei.com/Altitude%20Alert%20Super%20Clock%20ASC-5A.htm)
as the reminder. I have to tap the roll trim once or twice as one wing
gets lighter than then other, but it's no big deal.
The direct feed system
has worked flawlessly. I have even accidentally taken off pulling from a
wing tank and forgetting to turn on the boost pump... no problems at all.
I have tested (at altitude) the direct feed in turns rolled into the active
tank, and have only been able to unport the inlet in an extreme (full ball
deflection) slip. So long as the ball was centered, no amount of roll
would unport the tank.
Last summer I had a major
fuel leak in the cockpit during a cross-country. VERY SCARY! It
turned out that one of the clear plastic transfer lines had cracked. All
of the clear plastic lines in the cockpit had hardened and become brittle.
They were ten years old. I removed the transfer lines completely and
capped off the Facet pumps and the inlets to the header. I replaced the
tubing that forms the fuel gauge for the header tank. I do not miss the
transfer system at all!
Lee Metcalfe
N320WH - LNC2 - IO-320+ -
514 hrs. - Kansas City
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