X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [64.4.51.87] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.3.2) with ESMTP id 968018 for flyrotary@lancaironline.net; Mon, 30 May 2005 14:43:39 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.4.51.87; envelope-from=lors01@msn.com Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Mon, 30 May 2005 11:42:53 -0700 Message-ID: Received: from 64.4.51.220 by BAY107-DAV15.phx.gbl with DAV; Mon, 30 May 2005 18:42:53 +0000 X-Originating-IP: [64.4.51.220] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: will EFI pumps pump air Date: Mon, 30 May 2005 14:42:48 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00FA_01C56525.D933E7A0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MimeOLE: Produced By MSN MimeOLE V9.10.0011.1703 Seal-Send-Time: Mon, 30 May 2005 14:42:48 -0400 X-OriginalArrivalTime: 30 May 2005 18:42:53.0437 (UTC) FILETIME=[6361E2D0:01C56547] This is a multi-part message in MIME format. ------=_NextPart_000_00FA_01C56525.D933E7A0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I'd worry about the condition where the transfer tank was empty (air = leak through Facet). They are not "air-tight".=20 Tracy ----- Original Message -----=20 From: Bob White=20 To: Rotary motors in aircraft=20 Sent: Monday, May 30, 2005 12:51 PM Subject: [FlyRotary] Re: will EFI pumps pump air I'm 'T'ing the output of the transfer pump into the supply line from the main tank before the gascolator. The transfer pump will only have to overcome the head of the fuel, about 3 feet or so to push fuel back into the main tank. Is there anything I'm missing that would keep = this from working? Bob W. On Mon, 30 May 2005 10:51:53 -0500 "Russell Duffy" <13brv3@bellsouth.net> = wrote: > Will the EFI pump move enough air through it to disturb the fuel = rail > pressure that's being delivered from the other pump, =20 > I would say yes =20 > =20 > =20 > I'd bet that you have a 50-50 chance of being right :-) Seriously, = I'm not > so sure it would pump air well enough to overcome the 43 psi of = pressure > that the other pump is putting in the rail. I guess the only way to = find > out it to do the experiment. I'm not completely sure that's what I = want to > do anyway. =20 > =20 > Yep, still trying to figure out how to fix my fuel transfer system. = =20 > What's it look like now?=20 > =20 > =20 > 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. =20 > =20 > 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. >=20 > =20 > 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. =20 > =20 > Rusty =20 >=20 --=20 http://www.bob-white.com N93BD - Rotary Powered BD-4 (real soon) >> Homepage: http://www.flyrotary.com/ >> Archive: = http://lancaironline.net/lists/flyrotary/List.html ------=_NextPart_000_00FA_01C56525.D933E7A0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
I'd worry about the condition where the transfer tank was empty = (air leak=20 through Facet).   They are not "air-tight". 
 
Tracy
----- Original Message -----
From: Bob White
To: Rotary motors in = aircraft
Sent: Monday, May 30, 2005 = 12:51 PM
Subject: [FlyRotary] Re: will = EFI pumps=20 pump air

I'm 'T'ing the output of the transfer pump into the = supply line=20 from
the main tank before the gascolator.  The transfer pump = will only=20 have
to overcome the head of the fuel, about 3 feet or so to push = fuel=20 back
into the main tank.  Is there anything I'm missing that = would=20 keep this
from working?

Bob W.

On Mon, 30 May 2005 = 10:51:53=20 -0500
"Russell Duffy" <13brv3@bellsouth.net>=20 wrote:

> Will the EFI pump move enough air through it to = disturb the=20 fuel rail
> pressure that's being delivered from the other = pump, =20
>  I would say yes 
> 
>  =
>=20 I'd bet that you have a 50-50 chance of being right :-)   = Seriously,=20 I'm not
> so sure it would pump air well enough to overcome the = 43 psi=20 of pressure
> that the other pump is putting in the rail.  = I guess=20 the only way to find
> out it to do the experiment. I'm not = completely=20 sure that's what I want to
> do anyway. 
>  =
>=20 Yep, still trying to figure out how to fix my fuel transfer=20 system.  
>  What's it look like now? =
> =20
> 
> Remember the recent caution about copying a = system=20 100%, or it becomes a new
> system?  Well, guilty as = charged. =20 My system is just like Tracy's, except
> that I only have one = return=20 line to my feed tank.   I plumbed the wimpy
> facet = transfer=20 pump into the same line that returns from the regulator.
> That = means=20 the facet pump is trying to push against the return flow from = the
>=20 regulator, and it's not doing too well. 
> 
> = Even at=20 it's best, on the ground, with no other pumps on, the facet is = slow.
>=20 In the air, fighting against one EFI pump's return flow, it takes a=20 long
> long time to see fuel moving.  With both EFI pumps = on, I=20 almost wonder if
> fuel isn't going backwards into the non-feed = tank=20 anytime the facet wasn't
> on because the check ball isn't=20 perfect.  I added a one way valve to stop
> this, and to = stop the=20 fuel from leveling itself between tanks when parked.
> =
> =20
> The obvious solution is to "simply" (NOT) add another hose to = the=20 feed tank.
> Even if I go through all that hassle, I'm still = stuck with=20 the slow rate of
> transfer of the facet.  It's probably = still the=20 best option, but I'm going
> to investigate every other option = before=20 doing this. 
> 
>  Rusty 
>=20


--
http://www.bob-white.com
N93BD = - Rotary=20 Powered BD-4 (real soon)

>>  Homepage:  http://www.flyrotary.com/
>&= gt; =20 Archive:   http://lancai= ronline.net/lists/flyrotary/List.html
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