Subject: fuel system
From: Rotary Engine
Date: 7/30/2007, 10:52 AM
To: AARotary Engine



I am confused by all of the opinions out there and all of the
bad info mixed with the good on the internet.
Fuel lines out of the tanks, run forward to the console to a fuel
selector, then the main line run aft to gascolator with quick drain,
then dual pressure pumps, then through the firewall to a filter then to
dead-end fuel pressure regulator and fuel rail. If I keep fuel exposure
to heat at a minimum, can this work or am I way off?

Steve

I don't think you can dead end the fuel pressure regulator.
Watch out for the fuel selector on the Andair valve as the detents
are not strong. Put it some place so you can not inadvertently move it
with your
knee or some such. I investigated a fatal crash and that could have
been a factor.  Bulents two level brass valve works great but it
is a bit heavy.

Use positive displacement roller vane pumps and not the stock automotive
kind. Roller vane pumps will prime on their own when not mounted on the
bottom of the tank. Stock automotive pumps are designed to be installed
inside the fuel tank as is the Walbro even though you can get external
versions.
They don't suck well.

Several people have had good luck with the TWM
pressure regulator. I just check one for vacuum leaks on Marks engine
and the vac leak
was minimal. More than I can say about some other brands we have tested.
-- 
Paul Lamar ...No rotor no motor.



Paul,
Here is a photo and some info on the regulator I have. It is a
non-fuel-returning regulator. I thought it would be the way to go so I
didn't have to modify existing/finished tanks for a return. Maybe I blew
it. It sounds like I need to modify one or both tanks or build a header
tank (which I don't rally have room for).
My thought was that if I could keep gascolator, pumps etc. on the cool
side of the fire wall, then the fuel in the 12" or so of fuel line and
the fuel rail on the power plant side would stay cool enough to not need
a return...Thoughts?

Adjustable Mini Fuel Pressure Regulator
One of the lightest and smallest regulators on the market. Single inlet
and outlet, fuel pressure is adjustable from 50 to 75 PSI. 1:1 rising
rate, boost compatible. Comes with -6AN inlet/outlet fittings.

Steve Denny


I have no experience with that one. Get you self a hand vacuum tester (pump)
from the auto parts store and test it before you use it. Second picture.

BTW there is a lot of 3/16th dia. vacuum hose of slightly different sizes
on the market so test the entire  vac system for leaks starting at the intake
manifold.  This is critical on an EFI system that relies on intake manifold
pressure alone. It makes sense almost to use SS braided line as this
can bring your airplane down.
-- 
Paul Lamar ...No rotor no motor.

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