Date:         Sun, 5 Dec 1999 15:17:38 -0800
Reply-To:     Otmar List Account <otlists@EVCL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Otmar List Account <otlists@EVCL.COM>
Subject:      Auxiliary fuel tanks
Content-Type: text/plain; charset="us-ascii" ; format="flowed"

Speaking of gas tanks....

Has anyone made their own Aux tank? I plan to put one under the
passenger side floor, If anyone has diagrams or ideas that I could
copy it would be helpful. It looks like the location should hold 10
gallons. I need it because I made my own Syncro tank to clear the
diesel starter on the stretch and due to my laziness, I wanted to
make the shape easy to fabricate, it only holds 11 gallons.

I also need ideas on how to integrate it with the main tank which is
higher up in the original Syncro location. I would like it to be a
seamless integration so that it requires no input from the driver to
switch tanks. I figure I can put the two level sensors in series and
adjust them to run the fuel gauge that way.

I can see how to fill the extra tank at the same time by splitting
the filler pipe, but I'm not sure about how to draw the gas out. I
don't think I want to take the fuel draw off of the lower tank
directly to the engine because there isn't enough height to include a
low spot which would insure uninterrupted fuel flow. I would be
worried about drawing air in when the tank is low.

One solution I can imagine is that I could run a low pressure fuel
pump continuously from the lower tank to the upper tank. Then the
upper tank will be fed from the lower. As long as the upper tank is
more that 1/4 full then the fuel would spill back down the filler
pipe to the lower tank because the filler pipe on the Syncro enters
down low at about 1/4 tank.
When the lower tank runs dry and the upper one is below 1/4 tank, it
would run off the upper tank as usual.
I see one problem with this, that is that I need a fuel pump which
can safely and quietly run dry for extended periods of time. I know
that a "facet" pump could work, but they are very noisy, especially
when run dry.

Does anyone have ideas for a good "dry running" fuel pump or other
suggestions about the setup?
  -Otmar-
82/86 Stretch Vanagon Westfalia Syncro GTI. "Power of two"
http://www.evcl.com/strvan/strvan.html
Several EVs (Electric Vehicles)