John....thanks for the reply and information.  If I were to run my return to
the header tank, might it be beneficial to have the return fitting on the
bottom of the header tank, so the returned fuel would be forced into the
existing fuel, rather than dropping in from above and possibly mixing with
air between the top of the header tank and the top of the fuel level inside
the tank?  (Aerating), or would it be more difficult for the unused fuel to
be forced up into the existing fuel in the header tank?   Thanks again.
Paul Conner

Paul, I have a sump tank with internal fuel pumps.  The selected main
drains to the sump by gravity.  For that reason I found it best the main
fuel enter the sump tank at a low level near the bottom of the tank.  It
is fine to have the return fuel come in the top of the sump tank. There
should be no air in the tank if it is below the main tank.  I have my
sump tank vented, so the fuel level in the sump should rise into the
vent line to the same level as the fuel in the main tank.

--
Perry Mick
Custom Composite Props
mick@bridgingworlds.com
http://www.ductedfan.com

The AirCraft Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2002 All world wide rights reserved.