Return-Path: Received: from [206.46.170.137] (HELO out012.verizon.net) by logan.com (CommuniGate Pro SMTP 4.3c1) with ESMTP id 727766 for flyrotary@lancaironline.net; Sun, 13 Feb 2005 21:36:42 -0500 Received: from verizon.net ([4.12.145.173]) by out012.verizon.net (InterMail vM.5.01.06.06 201-253-122-130-106-20030910) with ESMTP id <20050214023642.IRGR15978.out012.verizon.net@verizon.net> for ; Sun, 13 Feb 2005 20:36:42 -0600 Message-ID: <42100EA4.3080702@verizon.net> Date: Sun, 13 Feb 2005 21:36:20 -0500 From: Finn Lassen User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 (ax; PROMO) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Vapor lock in sump/header tank. References: In-Reply-To: Content-Type: multipart/alternative; boundary="------------010009070400050208070102" X-Authentication-Info: Submitted using SMTP AUTH at out012.verizon.net from [4.12.145.173] at Sun, 13 Feb 2005 20:36:42 -0600 This is a multi-part message in MIME format. --------------010009070400050208070102 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit The first think I want to try is circulating the fuel from the "center" fuel pump back to the tank instead of shutting it off. Finn Ed Anderson wrote: > Finn, > > Per our conversation in Jan at LakeLand, I am 99% (well, 95%) > convinced that your bubbles are indeed due to heating and not air > leaks. When are you going to do a temp reroute of your fuel line away > from the bottom of the aircraft? > > Ed A > > ----- Original Message ----- > From: Finn Lassen > To: Rotary motors in aircraft > Sent: Sunday, February 13, 2005 8:23 PM > Subject: [FlyRotary] Re: Vapor lock in sump/header tank. > > I'm beginning to think that it takes very little heating to get > vapour on the suction side of the pumps. Probably especially with > auto gas. The lower the pressure, the lower the boiling point, right? > > Finn (still have not tried returning fuel from the "unused" pump > to the tank) > > Ed Anderson wrote: > >> In Paul's case, I am not certain it was vapor lock since he >> mentioned he found the his header tank cool to the touch. >> Certainly not a definitive temperature sensor - but a reasonable >> one. Certainly not to be discounted as a possible source of the >> problem and it possibility needs to be confirmed or eliminated. > --------------010009070400050208070102 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit The first think I want to try is circulating the fuel from the "center" fuel pump back to the tank instead of shutting it off.

Finn

Ed Anderson wrote:
Finn,
 
Per our conversation in Jan at LakeLand, I am 99% (well, 95%) convinced that your bubbles are indeed due to heating and not air leaks.  When are you going to do a temp reroute of your fuel line away from the bottom of the aircraft? 
 
Ed A
----- Original Message -----
Sent: Sunday, February 13, 2005 8:23 PM
Subject: [FlyRotary] Re: Vapor lock in sump/header tank.

I'm beginning to think that it takes very little heating to get vapour on the suction side of the pumps. Probably especially with auto gas. The lower the pressure, the lower the boiling point, right?

Finn (still have not tried returning fuel from the "unused" pump to the tank)

Ed Anderson wrote:
 In Paul's case, I am not certain it was vapor lock since he mentioned he found the his header tank cool to the touch.  Certainly not a definitive temperature sensor - but a reasonable one.  Certainly not to be discounted as a possible source of the problem and it possibility needs to be confirmed or eliminated.
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