Return-Path: Sender: "Marvin Kaye" To: lml@lancaironline.net Date: Wed, 22 Dec 2004 16:57:54 -0500 Message-ID: X-Original-Return-Path: Received: from imo-m22.mx.aol.com ([64.12.137.3] verified) by logan.com (CommuniGate Pro SMTP 4.2.5) with ESMTP id 577233 for lml@lancaironline.net; Wed, 22 Dec 2004 16:27:08 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.3; envelope-from=Sky2high@aol.com Received: from Sky2high@aol.com by imo-m22.mx.aol.com (mail_out_v37_r3.8.) id q.7d.5f4400e8 (4238) for ; Wed, 22 Dec 2004 16:26:39 -0500 (EST) From: Sky2high@aol.com X-Original-Message-ID: <7d.5f4400e8.2efb408f@aol.com> X-Original-Date: Wed, 22 Dec 2004 16:26:39 EST Subject: Re: [LML] An inch (MAP) ... A Hypothesis for Gear Heads X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1103750799" X-Mailer: 9.0 Security Edition for Windows sub 5000 -------------------------------1103750799 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 12/20/2004 1:13:48 P.M. Central Standard Time, Sky2high@aol.com writes: WOT, 184 KIAS, 214 KTAS, 21.2" MAP, 10.9 gph Reducing MAP about 1", 170 KIAS, 196 KTAS, 20.1" MAP, 8.9 gph A loss of 18 Knots (21 MPH) true airspeed. Then, at 12000 MSL, Baro 30.07, +1C OAT, 2500 RPM WOT, 175 KIAS, 213 KTAS, 20.1" MAP, 9.8 gph Reducing MAP 1", 162 KIAS, 195 KTAS, 19.1" MAP, 8.2 gph A loss of 18 Kts TAS. I talked to Arnie today to confirm his numbers and he added that the same drop in speed was shown by GPS Groundspeed. So......................... The only discrepancy that stands out is his MAP! My fuel flows only dropped .4-.5 gph, his dropped 1.6-2 gph, in line with a greater power reduction than just 1" MAP and, thus a greater speed reduction. Weather permitting, Arnie will go out and redo this experiment. But, now we both suspect his VM 1000 MAP sensor or some blockage. Query: Lorn mentioned that VM supplies a porous metal "filter" or "valve" for the MAP sensor (I don't have one) - if this was blocked or acting like a check valve this could contribute to false MAP readings. Does anyone know about these? Scott Krueger AKA Grayhawk N92EX IO320 Aurora, IL (KARR) -------------------------------1103750799 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

In a message dated 12/20/2004 1:13:48 P.M. Central Standard Time,=20 Sky2high@aol.com writes:

<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>

WOT, 184 KIAS, 214 KTAS, 21.2" MAP, 10.9 gph

Reducing MAP about 1",

170 KIAS, 196 KTAS, 20.1" MAP, 8.9 gph

A loss of 18 Knots (21 MPH) true airspeed.

Then, at 12000 MSL, Baro 30.07, +1C OAT, 2500 RPM

WOT, 175 KIAS, 213 KTAS, 20.1" MAP, 9.8 gph

Reducing MAP 1",

162 KIAS, 195 KTAS, 19.1" MAP, 8.2 gph

A loss of 18 Kts TAS.

I talked to Arnie today to confirm his numbers and he added that the sa= me=20 drop in speed was shown by GPS Groundspeed.

So.........................

The only discrepancy that stands out is his MAP! My fuel flows on= ly=20 dropped .4-.5 gph, his dropped 1.6-2 gph, in line with a greater power reduc= tion=20 than just 1" MAP and, thus a greater speed reduction. Weather=20 permitting, Arnie will go out and redo this experiment. But, now we bo= th=20 suspect his VM 1000 MAP sensor or some blockage.

Query: Lorn mentioned that VM supplies a porous metal "filter" or "valv= e"=20 for the MAP sensor (I don't have one) - if this was blocked or acting like a= =20 check valve this could contribute to false MAP readings. Does any= one=20 know about these?

Scott Krueger=20 AKA Grayhawk
N92EX IO320 Aurora, IL=20 (KARR)

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