X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 30 [X] Return-Path: Received: from fed1rmmtao102.cox.net ([68.230.241.44] verified) by logan.com (CommuniGate Pro SMTP 5.1.7) with ESMTP id 1907137 for flyrotary@lancaironline.net; Wed, 07 Mar 2007 10:34:11 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.241.44; envelope-from=alventures@cox.net Received: from fed1rmimpo02.cox.net ([70.169.32.72]) by fed1rmmtao102.cox.net (InterMail vM.7.05.02.00 201-2174-114-20060621) with ESMTP id <20070307153320.HQEU26279.fed1rmmtao102.cox.net@fed1rmimpo02.cox.net> for ; Wed, 7 Mar 2007 10:33:20 -0500 Received: from BigAl ([72.192.132.90]) by fed1rmimpo02.cox.net with bizsmtp id XrZK1W01A1xAn3c0000000; Wed, 07 Mar 2007 10:33:20 -0500 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: fuel filter Date: Wed, 7 Mar 2007 07:33:24 -0800 Message-ID: <001b01c760cd$f1fab4d0$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_001C_01C7608A.E3D774D0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_001C_01C7608A.E3D774D0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable John; =20 I agree with Ed; but will add that there should be some means of = trapping water before the pump. The pump can handle small particulates, but can disperse water which may allow some to get past a filter. A fine filter upstream from the pump is a vapor lock hazard; particularly if you = intend to run auto fuel. You gascolator will serve as the water trap before the = pump, but may also have a very fine screen, so it would be good check that frequently, particularly during initial operation. Gascolators are = adequate for carburetors, but for FI you'll want some finer filter downstream = from the pump; maybe 20 microns or so. =20 Al =20 =20 I personally believe placing a high pressure filter after the pump is = the preferred solution. I use a coarse filter (wire mesh) before the pump to keep any large foreign matter out of the pumps. If your injectors clog it doesn't matter what kind of filter you have before the pump or how well the pump is protected. Others will = argue that a fine filter before the pump protects both - unless of course the = pump starts to shed material. =20 One thing to consider is that a filter of any kind will cause a pressure drop, the finer it is (and therefore the more restrictive) the more of a pressure drop. Pressure drops before the intake of a pump can lead to cavitation and formation of bubbles in the fuel line leading to "vapor lock".=20 =20 In the auto, the screen inlet in the tank acts like a coarse filter ( = before the pump) and the filter outside the tank is a finer filter. =20 There you have my 0.02 on the topic =20 Ed ----- Original Message -----=20 From: John Downing=20 To: Rotary motors in aircraft=20 Sent: Wednesday, March 07, 2007 9:50 AM Subject: [FlyRotary] fuel filter =20 Looking at the pictures of fuel filter, pump installations, the filter = is after the pump. In auto installations the pump in tank has a screened = inlet and then filter someplace between the pump and the injection system. = The plane has a gascolator and do I place the pump next like auto = installations, then into the filter like the auto installations, or why not. JohnD ------=_NextPart_000_001C_01C7608A.E3D774D0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

John;

 

I agree with Ed; but will add that there should be some means of trapping = water before the pump.  The pump can handle small particulates, but can = disperse water which may allow some to get past a filter.  A fine filter = upstream from the pump is a vapor lock hazard; particularly if you intend to run = auto fuel.  You gascolator will serve as the water trap before the pump, = but may also have a very fine screen, so it would be good check that = frequently, particularly during initial operation.  Gascolators are adequate = for carburetors, but for FI you’ll want some finer filter downstream from the pump; = maybe 20 microns or so.

 

Al=

 

 

I personally believe = placing a high pressure filter after the pump is the preferred = solution.  I use a coarse filter

(wire mesh) before the pump = to keep any large foreign matter out of the pumps.  If your injectors clog = it doesn't matter what kind of filter you have before the pump or how well = the pump is protected.  Others will argue that a fine filter before the = pump protects both - unless of course the pump starts to shed = material.

 

One thing to consider is = that a filter of any kind will cause a pressure drop, the finer it is (and = therefore the more restrictive) the more of a pressure drop.  Pressure drops = before the intake of a pump can lead to cavitation and formation of bubbles in = the fuel line leading to "vapor lock".

 

In the auto, the screen = inlet in the tank acts like a coarse filter ( before the pump) and the filter = outside the tank is a finer filter.

 

There you have my 0.02 on = the topic

 

Ed

=

----- Original Message = -----

From: John Downing

Sent: Wednesday, March 07, 2007 9:50 AM

Subject: [FlyRotary] fuel filter

 

Looking at the pictures of = fuel filter, pump installations, the filter is after the pump.  In auto installations the pump in tank has a screened inlet and then filter = someplace between the pump and the injection system.  The plane has a = gascolator and do I place the pump next like auto installations, then into the filter = like the auto installations, or why not.  JohnD

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