Scott,

You're only dealing with a column of fuel 40" high and not the
weight of all 5 gallons.  Assuming the return line is 3/8th inch ID
(which would be on the big side), 40 inches works out to a grand total
of 4.4 cubic inches of fuel, or, a grand total of .11 lbs/sq in.

(Did I remember my grade 11 math correctly?)

Neil

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of Scott Stout
Sent: February 12, 2004 9:41 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] EFI Fuel Pressure

In a NA 13b setup, using the stock fuel pressure regulator what is the
pressure on the fuel rail?  Is this the ideal pressure?

Driving this question is I have to have to get fuel return fittings
welded to my tanks, well the highest point on the tank is not in the
easiest of spots to plumb to, thus I would like to return to a point
about half way down the tank.  So, not only does the fuel have to be
pumped up 40" or so it also has to overcome 5gal or so of fuel weight
above the return fitting.  External to the rotary lists, some of those
who I have floated the idea with have said the engine will run rich as
the fuel rail pressure will increase.  However, it doesn't seem to make
sense to me as the pressure in the fuel rail will probably be higher,
much higher, than the pressure needed to overcome the push through the
return fuel line.

What are your thoughts?

Thank You.

-Scott
http://home.att.net/~the_stouts_zenith_801/


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