Paul and group,

What size do you recommend for my fuel return line on my RX 8?  Would a 1/8" be large enough?   I  was reading some of your past e-mail about the pro's & con's on where to place the EFI fuel pumps.  My homebuilt plane (Bush Caddy) is a high wing aircraft, (no header tank) so would it be alright to bolt the pumps on the firewall (I'm running 3/8" feed line)?  Some are saying that the EFI pumps don't like to draw (suck) fuel that far. I don't want to place the pumps on the inside of the cabin as I have seen others do. Thoughts & suggestions?

Thanks,
Bob Forbes
Bush Caddy
N164WF

I think 1/8th is too small. It might defeat the pressure regulator
-6 or 3/8 is about right.

High wing tanks are great. Hard to screw them up :)
Left Right Both Off selectors work great but you will
still need a two level selector to return fuel to the
tank you are taking it from. If you put a header tank
in and vented it up high you would need no selector
and all return fuel could go to the header tank.
Probably one of the most error free systems possible.
Just don't point any vents into the wind as dynamic air
pressure can transfer fuel around in sometimes un wanted
ways.

Pumps on lower firewall would be fine in either case.


Paul Lamar