From: "Marvin Kaye" <marv@lancaironline.net>
Subject: Re: [FlyRotary] Re: Vapor Lock
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Date: Tue, 15 Feb 2005 21:50:52 -0500
Message-ID: <web-740922@logan.com>
In-Reply-To: <list-740909@logan.com>
References: <list-740909@logan.com>
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Hi Paul,

The system I described in my prior post was one that didn't include a sump or 
header tank... fuel flow was direct from the wing tanks.  Component sequence 
was as follows:
wing tanks > shutoff ball valves > fuel filters > HP fuel pumps > secondary 
bypass circuits > fuel selector > fuel pressure transducer > fluel flow 
transducers > firewall penetration > T to split flow to fuel rails > fuel 
rails > FP regulator > return through fuel selector to selected tank

The shutoff ball valves are hidden in the wing root fairings and allow flow 
from the tanks to be disabled to make it possible to remove & service the 
filters and pumps without having to drain the tanks.  Their handles are 
oriented so that they cannot be closed when their access panels are installed.

If your "sump" tank is truly a sump, I don't understand the need for the Facet 
boost pump... the sump should be fed by gravity from the mains.  If it needs 
to have fuel pumped up to it then it's a header.

   <marv>


"Paul" <sqpilot@bellsouth.net> wrote:

  I'm a little confused...I have both.  I have a facet low pressure boost pump
between the fuel selector and sump tank, and two high pressure EFI pumps after
the sump tank, before the engine.  Paul Conner
   ----- Original Message -----
   From: WRJJRS@aol.com
   To: Rotary motors in aircraft
   Sent: Monday, February 14, 2005 2:15 PM
   Subject: [FlyRotary] Re: Vapor Lock
  
  
   In a message dated 2/13/2005 10:09:15 AM Pacific Standard Time,
marv@lancaironline.net writes:
  
  
     Other folks have reported fuel flow problems when they located their 
pumps
     between the engine and fuel selector instead of between the fuel selector
and
     tanks... mostly the cause was air being sucked past the fuel selector's
seals
     causing some air to be introduced into the fuel flow.
  
  
   Good Point Marv,
   Bill Jepson
  
  
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