I would like to get some idea, what is the best way to build the fuel

 > return system of the 13b in a Cozy. Per plans we have two tanks with
 > fuel selector valve. I have my own ideas, but would like to hear from
 > some people with more experience.
 > How to prevent one tank from over filling by the return fuel, without
 > having a complicated pilot managed fuel system?
 > Bulent

When you break it down, there are only 4 solutions I can think of, there may
be more.  1)  Make the fuel return to a 'T" connector downstream of the fuel
valve. -   I have never heard of any specific reasons why this wont work, but
it seems to me that no one who knows what they are doing does it.  I think
that the problem has something to do with the necessity for the lowest
possible backpressure in the relief line, (although this doesn't make sense
to me because the pressure seen by the regulator wont change significantly
wherever you pump it to).  I have also heard that the reason for not using
this solution has to do with overheating of the fuel in the line and possible
vapor lock (again, this doesn't make sense to me because the physics say that
this fuel will not get significantly warmer than direct flow fuel).  I have
never heard of someone using this solution although it makes the most sense
to me...  maybe someone can enlighten me as to why this wont work?  

2)  Have
the fuel always come from one tank and use a pump to transfer between tanks.
- Tracy Crook uses this method as do several other installations I have
studied.  This is probably what I will do, unless I find something better.

3)  Dual line fuel control valves are available which will return fuel to the
tank from which it came.  I believe that this is the standard aircraft
solution but the valves are expensive and complicated.  

4)  Build a header
tank down stream of the fuel valve to send the return fuel into.  I believe
that Ed Anderson uses this solution but seems even more complicated than the
other solutions.

Let me know your thoughts.

Dave Leonard

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