Return-Path: Received: from [129.116.87.171] (HELO MAIL01.austin.utexas.edu) by logan.com (CommuniGate Pro SMTP 4.3c1) with ESMTP id 721624 for flyrotary@lancaironline.net; Wed, 09 Feb 2005 08:46:50 -0500 Received-SPF: none receiver=logan.com; client-ip=129.116.87.171; 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: multipart/alternative; boundary="----_=_NextPart_001_01C50EAD.97C9128D" Subject: RE: [FlyRotary] Re: Bad day at the airport Date: Wed, 9 Feb 2005 07:45:18 -0600 Message-ID: <87DBA06C9A5CB84B80439BA09D86E69EC07F21@MAIL01.austin.utexas.edu> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [FlyRotary] Re: Bad day at the airport Thread-Index: AcUOOb1kuRUQaCtlT5uffBYACJgsNAAcfkUQ From: "Mark R Steitle" To: "Rotary motors in aircraft" This is a multi-part message in MIME format. ------_=_NextPart_001_01C50EAD.97C9128D Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable =20 =20 ________________________________ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Al Gietzen Sent: Tuesday, February 08, 2005 5:55 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Bad day at the airport =20 Do you have a bleed circuit between your pump and fuel pressure regulator? Do you have heat shields on your fuel lines? My guess is that you may have experienced vapor lock. Without a bleed circuit, the fuel pump can't produce enough pressure to overcome the fuel pressure regulator =20 This should only be an issue if the pump is not located at the lowest point in the line from the tank. As long as there is liquid at the pump inlet - no problem. =20 Al =20 Al,=20 What happens if the lines in the engine bay and fuel pumps get hot enough for the fuel to boil inside them? Are the pumps still going to produce enough pressure to function normally? My guess is no. Paul said his coolant temp was 210+. He had been doing extended ground runs followed by some taxiing, which would allow for lots of heat soak and little cooling air. I imagine the fuel pumps and lines were pretty warm. Maybe warm enough to cause vapor lock. =20 =20 I would also like to know what type of fuel he was using at the time? If he was running mogas, has he checked the vapor pressure of the fuel? =20 Paul, do you have a return on your fuel system? If so, where does it return to? What size lines? =20 =20 Mark S. =20 =20 ------_=_NextPart_001_01C50EAD.97C9128D Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

 

 

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Al Gietzen
Sent: Tuesday, February = 08, 2005 5:55 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = Bad day at the airport

 

Do you have a bleed circuit between your pump and fuel = pressure

regulator? Do you have heat shields on your fuel lines? My guess is = that

you may have experienced vapor lock.  Without a bleed circuit, the = fuel

pump can't produce enough pressure to overcome the fuel = pressure

regulator

 

This should = only be an issue if the pump is not located at the lowest point in the line from = the tank.  As long as there is liquid at the pump inlet – no = problem.

 <= /font>

Al

 =

Al, =

What happens if = the lines in the engine bay and fuel pumps get hot enough for the fuel to boil = inside them?  Are the pumps still going to produce enough pressure to = function normally?  My guess is no.   Paul said his coolant temp was = 210+.  He had been doing extended ground runs followed by some taxiing, which = would allow for lots of heat soak and little cooling air.  I imagine the fuel = pumps and lines were pretty warm.  Maybe warm enough to cause vapor = lock.      

 =

I would also = like to know what type of fuel he was using at the time?  If he was running = mogas, has he checked the vapor pressure of the fuel?  =

 =

Paul, do you = have a return on your fuel system?  If so, where does it return to?  What = size lines?  =         =

 =

Mark = S.

 =

  =   

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