<VV> Mechanical Fuel Pump reverse flow?
Dave Morris "BigD"
BigD@DaveMorris.com
Wed, 29 Dec 2004 20:35:46 -0600
Yeah, I'm a student of William Wynne's conversion
(www.FlyCorvair.com). Until recently, he was recommending the mechanical
pump, but then starting talking about a leakage problem that prompted him
to install a catchment bowl under the pump to collect dripping fuel and
drain it away from the engine
(http://www.flycorvair.com/601sep046.jpg). He said you'd have to
re-tighten the screws on the housing several times to keep it from
leaking. Now he is recommending eliminating the mechanical pump altogether
and using dual electric pumps (http://www.flycorvair.com/601Sep2004.html)
I just thought if the leakage problem was solved, it would be better to
save 1.5 amps of constant current requirement and use a mechanical pump
that the engine was designed with.
Dave Morris
At 06:55 PM 12/29/2004, you wrote:
> The mechanical pump has two check valves to allow fuel moving in one
> direction only while the diaphragm pulsates so, if you connect both
> outlets, the fuel from the electric pump will not pass (reverse flow)
> thru the mechanical pump, assuming the check valves are in good
> condition. Pulsating electric pumps have check valves, too but don't know
> if rotary ones allow reverse flow or not.
> I remember having seen something about fuel pumps in airplanes at
> <http://flycorvair.com/>http://flycorvair.com/ , think you could get good
> ideas in this website.
>
> Daniel Monasterio
>
><<On my airplane's Corvair engine, I am planning to use the mechanical fuel
>pump but also have an electric fuel pump in parallel that I can switch in,
>in case of vapor lock or failure of the mechanical pump. Does anybody know
>whether the mechanical pump has a mechanism that would act as a check
>valve, preventing the reverse flow of fuel backward through the pump when I
>switch the electric one on?>>