Mailing List flyrotary@lancaironline.net Message #22756
From: Tracy Crook <lors01@msn.com>
Subject: Re: [FlyRotary] Re: will EFI pumps pump air
Date: Mon, 30 May 2005 14:33:45 -0400
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Message
Very strange Rusty, it should work unless you have a very low range Facet pump or have some restriction in return line.
 
  You *have* replicated my system because I also "T" the transfer pump into the EFI return line to feed tank.   It has no problem transferring fuel with this arrangement.  Facet makes these pumps in several different pressure ranges.  I think mine is the 4-6 psi model.   I used 3/8" line in this portion of system.  Did you use something smaller?
 
Tracy
 
Yep, still trying to figure out how to fix my fuel transfer system.   
 What's it look like now? 
 
 
Remember the recent caution about copying a system 100%, or it becomes a new system?  Well, guilty as charged.  My system is just like Tracy's, except that I only have one return line to my feed tank.   I plumbed the wimpy facet transfer pump into the same line that returns from the regulator.  That means the facet pump is trying to push against the return flow from the regulator, and it's not doing too well. 
 
Even at it's best, on the ground, with no other pumps on, the facet is slow.  In the air, fighting against one EFI pump's return flow, it takes a long long time to see fuel moving.  With both EFI pumps on, I almost wonder if fuel isn't going backwards into the non-feed tank anytime the facet wasn't on because the check ball isn't perfect.  I added a one way valve to stop this, and to stop the fuel from leveling itself between tanks when parked.   
 
The obvious solution is to "simply" (NOT) add another hose to the feed tank.  Even if I go through all that hassle, I'm still stuck with the slow rate of transfer of the facet.  It's probably still the best option, but I'm going to investigate every other option before doing this. 
 
 Rusty 
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