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Re: ram pressure

OK,  how about this:

Put the sump on the top of the firewall, and use one pump in each wing to
pump from the mains to the sump.  These pumps could be light weight.  That
you you will have 2 pumps.  If one fails, you have the other one working to
draw fuel.  You could plumb the tanks so that gravity feeds both tanks.
This way you don't have to worry about ram air to push the fuel.

173 FGE
-----Original Message-----
From: Brian K. Michalk <michalk@awpi.com>
To: Al Gietzen <alventures@email.msn.com>
Cc: reflector@awpi.com <reflector@awpi.com>
Date: Thursday, May 28, 1998 10:55 AM
Subject: Re: ram pressure

>> At least one issue would be vapor lock.  When the electrical pump fails
>> electric system failure) you have no pump.  May not be a problem during
>Hmm.  Okay.  Failure analysis:  What is more failure prone?
>I'm already installing dual batteries with primary and secondary
>busses.  Two boost pumps?  I don't know.
>> Or even without vapor lock; can you get enough flow to the carb for full
>> power operation without pressure?  Don't count on it!
>That's what the tests are for.  The Bingelis books outline tests
>for gravity feed.  You place the plane in level and at climb
>attitude.  Fill up the tanks and then make sure you get
>something like 1.5 times the fuel flow of max power operation.
>I'm not sure of the value, but it's like 1.5 or 2.  You have to
>go through all of the plumbing that includes filters and gascolators
>too.  Also make sure you are not getting any added benefit from
>siphoning.  Another thing is that you must get this sustained
>rate until the tanks are empty.
>I'd have to go look at the books again, but this is as well
>as I can recall at the moment.
>Brian Michalk  <http://www.awpi.com/michalk>
>Life is what you make of it ... never wish you had done something.
>Aviator, experimental aircraft builder, motorcyclist, SCUBA diver
>musician, home-brewer, entrepenuer and SINGLE!