X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 07 Jun 2007 11:30:29 -0400 Message-ID: X-Original-Return-Path: Received: from [68.98.211.24] (HELO systems3.net) by logan.com (CommuniGate Pro SMTP 5.1.9) with ESMTP id 2089361 for lml@lancaironline.net; Thu, 07 Jun 2007 11:06:36 -0400 Received-SPF: none receiver=logan.com; client-ip=68.98.211.24; envelope-from=cberland@systems3.net Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C7A915.5A4B5E7E" X-MimeOLE: Produced By Microsoft Exchange V6.5 Subject: [LML] Re: Hickman's Accident: NTSB Probable Cause Report X-Original-Date: Thu, 7 Jun 2007 08:05:57 -0700 X-Original-Message-ID: <87C33F695961494D886EB3B6C8A476512F38B2@s3server.Systems3.local> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [LML] Re: Hickman's Accident: NTSB Probable Cause Report Thread-Index: AcepEWCtrTGyhuLKRg64bH9UsJ1yDgAAa40Q From: "Craig Berland" X-Original-To: "Lancair Mail List" This is a multi-part message in MIME format. ------_=_NextPart_001_01C7A915.5A4B5E7E Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable =20 MikeEasley wrote: is the aneroid bellows that's been discussed the=20 feature of the fuel pump that richens the mixture at full throttle? =20 =20 The metering unit is a big player but here is what the aneroid does. The aneroid housing is referenced to deck pressure. The aneroid bellows expand when the air pressure surrounding it decreases. As the aneroid expands it moves the rod increasing the size of the orifice opening. An increased amount of fuel flows through the orifice to a recirculation path. This decreases fuel flow from the pump to the fuel metering unit. So as boost increases, fuel flow to the engine increases and boost decreases, fuel flow decreases due to the aneroid. =20 The fuel system on the TSIO550 is designed to allow high boost from an auxiliary pump to be used as a back up for engine pump failure. There is a check valve in the system for this purpose. Craig Berland ------_=_NextPart_001_01C7A915.5A4B5E7E Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable
 
MikeEasley wrote:  is the aneroid bellows that's = been=20 discussed the
feature of the fuel pump that richens the mixture at = full=20 throttle?  
 
The metering unit is a=20 big player but here is what the aneroid does. The aneroid housing = is=20 referenced to deck pressure.  The aneroid bellows expand when the = air=20 pressure surrounding it decreases.  As the aneroid expands it moves = the rod=20 increasing the size of the orifice opening.  An increased amount of = fuel=20 flows through the orifice to a recirculation path.  This=20 decreases fuel flow from the pump to the fuel metering unit.  = So as=20 boost increases, fuel flow to the engine increases and boost decreases, = fuel=20 flow decreases due to the aneroid.
 
The fuel system on the = TSIO550 is=20 designed to allow high boost from an auxiliary pump to be used as a = back up=20 for engine pump failure.  There is a check valve in the system for = this=20 purpose.
Craig=20 Berland
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