X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: <13brv3@bellsouth.net> Received: from imf21aec.mail.bellsouth.net ([205.152.59.69] verified) by logan.com (CommuniGate Pro SMTP 4.3.2) with ESMTP id 967898 for flyrotary@lancaironline.net; Mon, 30 May 2005 11:52:19 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.152.59.69; envelope-from=13brv3@bellsouth.net Received: from ibm63aec.bellsouth.net ([65.6.194.9]) by imf21aec.mail.bellsouth.net with ESMTP id <20050530155134.YVYE2486.imf21aec.mail.bellsouth.net@ibm63aec.bellsouth.net> for ; Mon, 30 May 2005 11:51:34 -0400 Received: from rd ([65.6.194.9]) by ibm63aec.bellsouth.net with ESMTP id <20050530155134.DHAS25209.ibm63aec.bellsouth.net@rd> for ; Mon, 30 May 2005 11:51:34 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: will EFI pumps pump air Date: Mon, 30 May 2005 10:51:53 -0500 Message-ID: <000001c5652f$80480900$6101a8c0@rd> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C56505.97720100" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2527 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C56505.97720100 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable 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 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 ------=_NextPart_000_0001_01C56505.97720100 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message
Will the EFI pump move enough air through it to = disturb=20 the fuel rail pressure that's being delivered from the other = pump,  
 I would say yes  
 
 
I'd bet that you have a = 50-50=20 chance of being right :-)   Seriously, I'm not so sure it = would pump=20 air well enough to overcome the 43 psi of pressure that the other pump = is=20 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
 
Yep, = still trying=20 to figure out how to fix my fuel transfer = system.   
 What's it = look like=20 now? 
 
 
Remember the recent caution about copying a = system=20 100%, or it becomes a new system?  Well, guilty as charged.  = My system=20 is just like Tracy's, except that I only have one return line to my = feed=20 tank.   I plumbed the wimpy facet transfer pump into the = same=20 line that returns from the regulator.  That means the facet pump is = trying=20 to push against the return flow from the regulator, and it's not doing = too=20 well. 
 
Even at=20 it's best, on the ground, with no other pumps on, the facet is = slow.  In=20 the air, fighting against one EFI pump's return flow, it takes a long = long time=20 to see fuel moving.  With both EFI pumps on, I almost wonder if = fuel isn't=20 going backwards into the non-feed tank anytime the facet wasn't on = because the=20 check ball isn't perfect.  I added a one way valve to stop = this, and=20 to stop the fuel from leveling itself between tanks when parked. =20  
 
The=20 obvious solution is to "simply" (NOT) add another hose to the = feed=20 tank.  Even if I go through all that hassle, I'm still stuck with = the=20 slow rate of transfer of the facet.  It's probably still the = best=20 option, but I'm going to investigate every other option before doing = this. =20
 
 Rusty =20
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