Best spot to mount Auxiliary fuel pump KF7

[mr bill]

Capacitor eliminates electrical system noise generated by the brushes in the motor. You see the same thing on the alternator.

[PNWJARED]

when we put the fuel pump behind the seat it pressurizes the fuel line from that point on. Pressurized fuel in the cabin? I suspect it is all pros and cons at that point.

[Av8r3400]

Pressurized fuel in the cabin concerned me also.

I plumbed all lines downstream from the auxiliary electric pump with hard aluminum lines for this reason. I only used two short pieces of hose from the tanks to the shut off valves and the header vent line are the only rubber fuel lines in the cabin on my plane.

[n85ae]

That's enough capacitor to function as a backup starter battery ... Probably
the pump runs for 10 minutes after you kick the switch off

Jeff

Capacitor eliminates electrical system noise generated by the brushes in the motor. You see the same thing on the alternator.

[Esser]

I don't need to see the need to put the pump further back. Yes, pumps push better than pull but your pump is constantly primed by the gravity head pressure of your high wing tanks. If you mount your pump low on the fire wall the only time it would really have to "suck" fuel is once your header was less than half empty.

[jiott]

Yes but consider this: the only reason you install an auxiliary fuel pump is in case of partial blockages in the fuel lines or filters. Under normal conditions the gravity head alone is enough to feed the engine. If you get a partial blockage in a long suction line (pump mounted far forward) the weak sucking ability of the pump in addition to the restricted and long line probably will not be enough to pump adequate fuel to the engine. Whereas a much shorter suction line may be able to suck adequately even with a partial blockage.