X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 16 Jul 2007 07:03:04 -0400 Message-ID: X-Original-Return-Path: Received: from imo-m26.mx.aol.com ([64.12.137.7] verified) by logan.com (CommuniGate Pro SMTP 5.1.10) with ESMTP id 2179531 for lml@lancaironline.net; Sun, 15 Jul 2007 21:07:42 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.7; envelope-from=Sky2high@aol.com Received: from Sky2high@aol.com by imo-m26.mx.aol.com (mail_out_v38_r9.2.) id q.bdd.171c0c0e (39331) for ; Sun, 15 Jul 2007 21:06:56 -0400 (EDT) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Sun, 15 Jul 2007 21:06:56 EDT Subject: Re: [LML] L360 Fuel pressure X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1184548016" X-Mailer: 9.0 Security Edition for Windows sub 5365 X-Spam-Flag: NO -------------------------------1184548016 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 7/15/2007 7:30:20 P.M. Central Daylight Time, randy@aoaircrafters.com writes: What fuel pressure range should I be seeing for a Lycoming IO-360 in a Lancair 360 (N360DE)? Randy, This may not be relevant. The Lycoming Manual for a IO 320 states that the fuel pressure can be between 12 and 50 psi. I would check the appropriate Lyc engine manual. It has generally been the case that 26-28 psi is maintained for normal operation of my 320. My measurement is taken from a tee at the exit of the engine driven pump with a fine-hole restrictor in the tee. There are operational problems when the pressure drops to or below 12 psi and everything is hot as this allows vaporization to occur in the system anywhere after the engine driven pump. As a matter of fact, sometimes the pressure drops because of vapor induced cavitation of the engine pump. This is fixed by application of the boost pump. Is it possible that the flow by the tee is artificially reducing the pressure seen by the sensor because your tee is in the flow stream (Bernoulli)? It is reasonable that the boost pump only adds +2 psi (that's what mine does), thus it is hard to imagine both pumps being bad - i.e. delivering lo pressure. Scott Krueger AKA Grayhawk Lancair N92EX IO320 SB 89/96 Aurora, IL (KARR) Darwinian culling phrase: Watch This! ************************************** Get a sneak peak of the all-new AOL at http://discover.aol.com/memed/aolcom30tour -------------------------------1184548016 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
In a message dated 7/15/2007 7:30:20 P.M. Central Daylight Time,=20 randy@aoaircrafters.com writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>

What=20 fuel pressure range should I be seeing for a Lycoming IO-360 in a Lancair=20= 360=20 (N360DE)?

 <= /FONT>

Randy,
 
This may not be relevant.  The Lycoming Manual for a IO 320 states= =20 that the fuel pressure can be between 12 and 50 psi.  I would check the= =20 appropriate Lyc engine manual.  It has generally been the case that 26-= 28=20 psi is maintained for normal operation of my 320.  My measurement is ta= ken=20 from a tee at the exit of the engine driven pump with a=20 fine-hole restrictor in the tee.  There are operational probl= ems=20 when the pressure drops to or below 12 psi and everything is hot as thi= s=20 allows vaporization to occur in the system anywhere after the engine driven=20 pump.  As a matter of fact, sometimes the pressure drops because of vap= or=20 induced cavitation of the engine pump.  This is fixed by application of= the=20 boost pump.
 
Is it possible that the flow by the tee is artificially reducing the=20 pressure seen by the sensor because your tee is in the flow stream=20 (Bernoulli)? 
 
It is reasonable that the boost pump only adds +2 psi (that's what mine= =20 does), thus it is hard to imagine both pumps being bad - i.e. delivering lo=20 pressure. 
 
Scott Krueger=20 AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL=20 (KARR)

Darwinian culling phrase: Watch=20 This!



Get a sneak p= eak of the all-new AOL.com.
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