Engine driven fuel pump necessary with gravity feed tank?? Lycoming

[RonLee]

Situation with experimental airplane:
Gravity feed tank with Lyc IO320B1A fuel injected engine.
Gravity free fuel flow is greater than 20 gph and the engine burns 15
gph at full throttle take off.
Cruse fuel flow 7.5 to 8 gph.

I want to test the engine without the engine driven fuel pump as I
feel it is not a necessary item. For start priming the engine I use an
electric fuel pump (Dukes).

Any one have knowledge of this situation? Perhaps the fuel injected
engine needs the fuel pressure

All comments welcome.........thanks

[[email protected]]

On Sun, 08 May 2005 02:02:55 GMT, RonLee >
wrote:

>Situation with experimental airplane:
>Gravity feed tank with Lyc IO320B1A fuel injected engine.
>Gravity free fuel flow is greater than 20 gph and the engine burns 15
>gph at full throttle take off.
>Cruse fuel flow 7.5 to 8 gph.
>
>I want to test the engine without the engine driven fuel pump as I
>feel it is not a necessary item. For start priming the engine I use an
>electric fuel pump (Dukes).
>
> Any one have knowledge of this situation? Perhaps the fuel injected
>engine needs the fuel pressure
>
>All comments welcome.........thanks

"generally" injection requires pressure. Otherwize it's just
dribbling.

[[email protected]]

Check the FARs. In Canada, at least, a gravity fed fuel system must
flow 150% of max required fuel flow in the most critical attitude for
flight with minimum fuel aboard. A pump system requires 125%. Your 20
gph won't cut it.

Dan