On Oct 20, 8:43*am, flybynightkarmarepair wrote:
On Oct 19, 5:31*pm, Jerry Wass wrote:





wrote:
Have you looked at an Ercoupe fuel system? Two wing tanks in common
(IIRC), pumping with a mech. pump, continuously to a small (5 gal.?)
header tank. Header tank overflows back to a wing tank when it's full..
Header tank feeds the engine via gravity flow.
When the wing tanks are empty, the header tank float & wire gauge
begins to drop. At the moment, you know exactly how much fuel is left..
Works excellently and is very simple. If the pump fails, you still
have the header tank.

Rich S.

I wonder about paralleling the pumps, instead of series.---If you run
both for takeoff/landing you get double the pressure..(may flood engine)
In series, if one stops up w/trash, there's no route around it.
there's a very small leak back orifice to prevent
Heat-expansion/flooding. *Jerry

RE the Ercoupe example: I don't like header tanks from a crash safety
standpoint, and another vent, and a return line souunds like MORE
plumbing to me. *Plus, this is a VW conversion, and if I used a
mechanical fuel pump it would be on the TOP of the engine, plus they
are not sealed like aircraft mechanical fuel pumps are, so this is a
no-go.

Paralleling the pumps also introduces more fittings. *There are finger
strainers in the fuel tanks to keep out the big crap, plus the fuel
pumps only see fuel coming FROM the gascolator, so that failure mode -
jamming due to FOD - seems to unlikely to plan around, IMHO. *I'm more
concerned about an electrical fault, or the failure of the pump itself
due to some internal fault, thus Series makes more sense to me. *And
the pumps already have more than enough flow for full throttle.

Thanks for the feedback, it keeps me thinking, the point of the
exercise.- Hide quoted text -

- Show quoted text -

Ryan,
I fully understand your dislike of a header tank, but have you
considered a small fuel cell instead. You achieve enhanced fire safety
as well as a centralized fuel gathering site which would feed to the
gascolator. Also insofar as fuel pumps are concerned what are the
possibilities regarding the use of an electric fuel pump?
Joe