X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [129.116.87.143] (HELO MAIL01.austin.utexas.edu) by logan.com (CommuniGate Pro SMTP 4.3.4) with ESMTP id 1001830 for flyrotary@lancaironline.net; Tue, 14 Jun 2005 15:13:51 -0400 Received-SPF: none receiver=logan.com; client-ip=129.116.87.143; envelope-from=mark.steitle@austin.utexas.edu X-MimeOLE: Produced By Microsoft Exchange V6.5.7226.0 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Subject: RE: [FlyRotary] Re: fuel pump mounting ( fuel system architecture) Date: Tue, 14 Jun 2005 14:13:06 -0500 Message-ID: <87DBA06C9A5CB84B80439BA09D86E69E016C1A18@MAIL01.austin.utexas.edu> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [FlyRotary] Re: fuel pump mounting ( fuel system architecture) Thread-Index: AcVxDrambICdG408SfyVOHFIDATJRQABOsaA From: "Mark R Steitle" To: "Rotary motors in aircraft" John,=20 At risk of repeating myself, I would like to add to John's comments. =20 I ran a similar test, but included the rest of the fuel system (Andair valve, fuel filters, fuel rail, fuel pressure regulator, etc.) and found out that my system would not reprime unless I cracked open a line downstream of the pump. With the addition of the bypass bleed circuit, I have confirmed that one dry pump will draw fuel up from the floor (approx. 18") through the Andair valve and be up to pressure in about 10 seconds. "Time to prime" is significantly reduced by running both pumps. I have repeated the test using auto fuel in hot Texas temps and get similar results.=20 Mark S. Lancair ES w/20B -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of John Slade Sent: Tuesday, June 14, 2005 1:27 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: fuel pump mounting ( fuel system architecture) > > I did an experiment with the pump on a 4 foot bench, and a gas can > > on the > > floor. The pump primed itself with no difficulty. Having said that, > > a > > scenario like this in a plane would be just asking for vapor lock. > > > ----------------------------------------------- > > Hi John, I like your test but do not understand your conclusion. The conclusion wasn't based on the results of the experiment :) It's my understanding that you need to replicate the temperatures and pressures for the experiment to be entirely valid. > If the pump will prime with a 4 foot negative head that sounds good to me. But this only proves it works on the bench under atmospheric pressure and ambient temperature. John >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html