X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 29 Sep 2014 07:15:44 -0400 Message-ID: X-Original-Return-Path: Received: from nk11p08mm-asmtp002.mac.com ([17.158.58.247] verified) by logan.com (CommuniGate Pro SMTP 6.0.9e) with ESMTPS id 7176039 for lml@lancaironline.net; Thu, 25 Sep 2014 20:40:22 -0400 Received-SPF: pass receiver=logan.com; client-ip=17.158.58.247; envelope-from=gw5@me.com Received: from [192.168.0.14] (cpe-071-077-208-151.ec.res.rr.com [71.77.208.151]) by nk11p08mm-asmtp002.mac.com (Oracle Communications Messaging Server 7u4-27.10(7.0.4.27.9) 64bit (built Jun 6 2014)) with ESMTPSA id <0NCH00GSKGG9GG80@nk11p08mm-asmtp002.mac.com> for lml@lancaironline.net; Fri, 26 Sep 2014 00:39:32 +0000 (GMT) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.12.52,1.0.28,0.0.0000 definitions=2014-09-26_01:2014-09-25,2014-09-25,1970-01-01 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 suspectscore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=7.0.1-1402240000 definitions=main-1409260006 From: George Wehrung Content-type: multipart/alternative; boundary=Apple-Mail-72C60B4E-4422-4CD4-9249-FF2EDC109710 Content-transfer-encoding: 7bit MIME-version: 1.0 (1.0) Subject: Re: [LML] Re: Mechanical Fuel Pump Oddities X-Original-Message-id: <52359751-B66C-4A4A-AD2F-A8B89382C397@me.com> X-Original-Date: Thu, 25 Sep 2014 20:39:35 -0400 References: In-reply-to: X-Original-To: Lancair Mailing List X-Mailer: iPad Mail (12A365) --Apple-Mail-72C60B4E-4422-4CD4-9249-FF2EDC109710 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable I am watching Bill Ross' webinar and of course it's everything you taught me= . Sent from my iPad > On Sep 24, 2014, at 13:21, Neal George wr= ote: >=20 > =E2=80=A6so the best explanation could be =E2=80=9Cthey do that=E2=80=9D. > =20 > Yeah=E2=80=A6elevated fuel temps, high altitude/low atmospheric pressure, i= ncreased head differential due to climb attitude, vent restrictions (bugs an= d fuel stains), and the engine-driven pump trying to suck fuel uphill thru t= he restrictions of fittings, valves and twisting hoses & tubes all conspire t= o lower the system pressure. When the system pressure is lower than the vap= or pressure of the fuel, it boils. > =20 > I=E2=80=99ve also seen fuel lines and boost pumps leak air under suction t= hat don=E2=80=99t leak fuel under pressure. > =20 > When (before) your Dukes pump goes, consider CJ Aviation ( www.cjaviation.= com ) for a replacement or overhaul=E2=80=A6 > =20 > Neal =20 > =20 > From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Ste= ve Colwell > Sent: Wednesday, September 24, 2014 6:13 AM > To: Lancair Mailing List > Subject: [LML] Mechanical Fuel Pump Oddities > =20 > Kevin, > =20 > I had the same problem on a warm day with warm fuel from an above ground t= ank. My solution is to leave Low Boost on all the time. The Dukes pump is n= ot rated for continuous operation but mine is still running at 200+ hours. A= nother plus is, if your engine pump fails on takeoff, Low Boost will probabl= y keep the engine running (maybe at reduced power but still running). I bel= ieve Continental recommends Low Boost above 10,000=E2=80=99 so the best expl= anation could be =E2=80=9Cthey do that=E2=80=9D. > =20 > Steve Colwell IO-550 Legacy --Apple-Mail-72C60B4E-4422-4CD4-9249-FF2EDC109710 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable

I am watching Bill Ross' webinar and o= f course it's everything you taught me.

Sent from my iPad

<= br>On Sep 24, 2014, at 13:21, Neal George <ngeorge@continentalmotors.aero> wrote:

=

=E2=80=A6so the best explanation could be =E2=80=9Cth= ey do that=E2=80=9D.

Yeah=E2=80=A6elevated fuel temps, high altitude/low atmospheric pr= essure, increased head differential due to climb attitude, vent restrictions (bugs and fuel stains), and the engine-driven pump trying= to suck fuel uphill thru the restrictions of fittings, valves and twisting h= oses & tubes all conspire to lower the system pressure. When the system pressure is lower than the vapor pressure of the fuel= , it boils.

I=E2=80=99ve also seen fuel lines and boost pumps leak air under s= uction that don=E2=80=99t leak fuel under pressure.

When (before) your Dukes pump goes, consider CJ Aviation ( www.cjaviation.com ) for a replace= ment or overhaul=E2=80=A6

Neal

From: Lancair Mailing List [mailto:lml@lancairon= line.net] On Behalf Of Steve Colwell
Sent: Wednesday, September 24, 2014 6:13 AM
To: Lancair Mailing List
Subject: [LML] Mechanical Fuel Pump Oddities

Kevin,

I had the same problem on a warm day with warm fuel f= rom an above ground tank. My solution is to leave Low Boost on all the= time. The Dukes pump is not rated for continuous operation but mine i= s still running at 200+ hours. Another plus is, if your engine pump fails on takeoff, Low Boost will probably keep the e= ngine running (maybe at reduced power but still running). I believe Co= ntinental recommends Low Boost above 10,000=E2=80=99 so the best explanation= could be =E2=80=9Cthey do that=E2=80=9D.

Steve Colwell IO-550 Legacy

= --Apple-Mail-72C60B4E-4422-4CD4-9249-FF2EDC109710--