Chrissi, This whole pump thread makes my head hurt just reading it!
I hope it is much eaiser to use than it sounds. Your racing

experience

will help here, (keeping things straight when under extreem

stress),

but the item we all need to remember is, READ ALONG WITH ME,
THE MOST COMMON FAILURE OF EXPERIMENTAL AIRCRAFT
IS ENGINE OUT OR LOSS OF POWER DUE TO FUEL FEED
PROBLEMS. The FAA says over 30% of homebuilts have some sort
of fuel related problem in the first 40 hours. I have even seen
higher percentage figures used in some studys. I am working on
a one-design aircraft for a future build and it will have fuel

tanks

that are finished and tested outside the aircraft no matter how
hard this might be. I can't see why when we have so much tied
up in our planes everybody wants to use some complicated fuel
arrangement. Bulent had a good looking valve, but I haven't seen
one other one I would trust. Spend the money get a good andair
valve, or the equivlent,  as us engineers like to say. Then

practice

in your hangar and TRY TO MAKE IT FAIL. If you can't make the
engine stop without cutting the mains your ready! You won't
be supprised. Sorry for the length this is a pet peeve of mine.
Bill Jepson

You are right Bill. Looks too complicated to me also. I will be

avoiding all

the sump tanks, remote controlled valves or the $400 Andair jewel,

which BTW

has very small ports. I just use this very nice 6 port valve and all

of the

above complications go away. It has ON/OFF L/R and Both positions with

very

nice detent when centered on the port.
Bulent

Steve Hall wrote:

Why have a valve at all??
Sump tank and two fuel pumps is all that is needed!!

Steve

We are worried about the heat introduced into the return flow.
Although the Subaru data indicates this may not be as big a problem as
we think it is.

Paul Lamar

-"Jeffery J. Andre'" wrote:

Why doesn't someone who has an EFI pump sitting around simply take a 5
gallon gas can, put a few gallons in it and hook up one (or two) EFI pumps
to pump fuel out and right back in?  You can measure the temp rise from
start to finish (say a half hour run).  Granted, it may pick up a little
more heat running through the fuel rail, but it should answer the question
reasonably clearly.  My bet would be that any additional heat picked up
through the rail would be offset by the fresh fuel flow from the main tanks
(probably more than offset).

Everyone can then stop speculating and trying to plan around a problem that
may well not exist.

(back to quietly watching the regularly scheduled programming)

Jeff Andre
Raleigh, NC

Good Idea Jeff. Only through the actual fuel rail on a running engine that
is warm. Do it on the ground as it is too risky to do it in the air with only
two gallons.

Paul Lamar
 
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