Message-ID: <3F8E9813.418CD601@frontiernet.net>
Date: Thu, 16 Oct 2003 09:07:31 -0400
From: Jim Sower <canarder@frontiernet.net>
MIME-Version: 1.0
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Fwd: Fuel systems
References: <list-2638931@logan.com>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

Joe,
This very issue was debated quite extensively on a couple of Cozy lists.  My
solution is as follows:
Both wing tanks gravity feed to a sump.  Water drain is in the sump.
The sump outlet "T"s into two parallel high pressure fuel pumps with filters.
Appropriate check valves.
Pump output "T"s into fuel injection rail.
Return goes to Right tank only.

An option if I don't use a sump is to have the fuel pumps each draw from one
tank, but still have the rail return to the Right tank.  I would switch tanks
(pumps) back and forth in flight.  I will need a Facet pump to transfer last
few gallons from Left tank to Right and ensure at the end of a flight that
every drop of fuel I own is in the "selected" tank.  This system has the
disadvantage that if Right pump fails, Left pump keeps the engine running, but
I am pumping at least as much fuel into the "inaccessible" tank as I am
burning.  This could be solved with two Facet pumps.

Both systems have no valves or plumbing in the cabin.  I would have manual
maintenance valves between each wing tank and the sump, and perhaps an
electrical emergency shutoff either just before or just after the main pumps
(electrically Closed, fails Open), but shutting off the fuel pumps would serve
the same purpose.

Hope this helps ... Jim S.

Joseph Berki wrote:

> >
> >Hi,
> >         I know that this has been discussed before but I still have not
> > found a good solution. The Limo EZ (same as Long EZ) has two tanks mid
> > wing design.  Original design requires fuel from both tanks to be fed to
> > a valve and then back to the engine.  Problem, fuel injection requires
> > special valve to return fuel to tank it was delivered from.   This means
> > 3 more lines in addition to the 3 lines already in the cockpit.  I think
> > this is getting complicated.  I like the sump idea creating one tank but
> > the problem is return.  If you return it to the sump you heat the fuel in
> > the sump up.  Is there any way to divide the fuel return so it can be
> > returned to both tanks?  If you tee the return lines does the fuel divide
> > evenly?  I thought about another sump to return the fuel to and let it
> > drain into both tanks.  Make it higher than the delivery sump. I am
> > trying to avoid a transfer pump but it would need two lines instead of 3
> > and they could be placed outside the cockpit.  What about using two pumps
> > that can be synchronized?  One could pump fuel from the right tank to the
> > fuel rail and the other could transfer fuel from the left tank to the
> > right tank depending on the fuel flow being pumped from the right
> > tank?  Return fuel would go the the left tank making a continuous loop
> > allowing the fuel to cool? I keep thinking of my friends Bellanca with 5
> > fuel tanks a fuel management nightmare.  Thanks for any help.
> >
> >Joe Berki
> >Limo EZ
>
> >>  Homepage:  http://www.flyrotary.com/
> >>  Archive:   http://lancaironline.net/lists/flyrotary/List.html

--
Jim Sower
Crossville, TN; Chapter 5
Long-EZ N83RT, Velocity N4095T