Mailing List flyrotary@lancaironline.net Message #17385
From: Jim Sower <canarder@frontiernet.net>
Subject: Re: [FlyRotary] Re: Vapor Lock
Date: Thu, 17 Feb 2005 13:02:48 -0600
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
<... tried removing it and heating the engine as in previous tests to see if you  get a vapor lock ...>
I wouldn't do that, at least permanently.  It was your Facet pump enabled you to re-prime the HP pump the last time it quit wasn't it?  Your long lines to the selector are a MUCH bigger restriction than the Facet pump.  Even if it doesn't quit after you remove the Facet, you've given away the only way you have to re-prime the HP pump when it DOES quit again (and it probably will).  My fix would be to set your fuel system up like Tracy's.

Don't give away your restart capability ... Jim S.

Kelly Troyer wrote:

Paul,
  I have forgotton your exact fuel system layout.......Do your efi pumps push
fuel from sump tank to fuel valve then to engine or are they installed after the
fuel valve and suck fuel from all the way back to the sump tank  ?  I tend to
agree with Tracy and others that the Facet boost pump is a restriction.....Have
you tried removing it and heating the engine as in previous tests to see if
you  get a vapor lock ?
--
Kelly Troyer
Dyke Delta/13B/RD1C/EC2

    -------------- Original message from "Tracy Crook"
    <lors01@msn.com>: --------------

    The Facet pump in this position is a two edged sword.  It can help
    eliminate a vapor lock when on but it is a restriction that can
    create a vapor lock when off.   A properly laid out fuel system
    should not require another pump to prime the main EFI pump.  It is
    a bandaid IMO.  Again, any restriction other than a strainer to
    stop the 'big chunks' before the EFI pumps is not a good thing.
         Tracy

         

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