X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 18 Oct 2009 11:42:37 -0400 Message-ID: X-Original-Return-Path: Received: from QMTA09.emeryville.ca.mail.comcast.net ([76.96.30.96] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3888966 for lml@lancaironline.net; Sat, 17 Oct 2009 00:27:21 -0400 Received-SPF: pass receiver=logan.com; client-ip=76.96.30.96; envelope-from=ijheizer@comcast.net Received: from OMTA19.emeryville.ca.mail.comcast.net ([76.96.30.76]) by QMTA09.emeryville.ca.mail.comcast.net with comcast id tg2B1c0061eYJf8A9gSnY0; Sat, 17 Oct 2009 04:26:47 +0000 Received: from sz0109.ev.mail.comcast.net ([76.96.26.169]) by OMTA19.emeryville.ca.mail.comcast.net with comcast id tgSm1c00D3eudEs01gSmz6; Sat, 17 Oct 2009 04:26:47 +0000 X-Original-Date: Sat, 17 Oct 2009 04:26:46 +0000 (UTC) From: Isaac Heizer X-Original-To: lml@lancaironline.net X-Original-Message-ID: <228195596.5105451255753606895.JavaMail.root@sz0109a.emeryville.ca.mail.comcast.net> In-Reply-To: <319340332.5105271255753486335.JavaMail.root@sz0109a.emeryville.ca.mail.comcast.net> Subject: Re: LOP MP setting for TSIO-550E MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_266532_683472257.1255753606895" X-Originating-IP: [98.247.34.240] X-Mailer: Zimbra 5.0.18_GA_3076.RHEL5_64 (ZimbraWebClient - FF3.0 (Win)/5.0.18_GA_3076.RHEL5_64) ------=_Part_266532_683472257.1255753606895 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit In the original email, i asked what MP one should use when running LOP. George Braly suggested i go out and find out for myself. So I did. Here are two runs, both LOP at 2500 RPM and 17.5 GPH lean of peak: 30" MAP EGT 1558 1558 1576 1563 1528 1484 CHT 330 328 332 328 340 324 TIT 1593 / 1634 31.6 MAP EGT 1542 1544 1556 1540 1514 1472 CHT 326 322 326 324 326 314 TIT 1578 / 1611 The IAS in both cases was the same, so the horsepower must have been the same. As one can see, higher MP means cooler temperatures. Which makes sense, since the mixture is leaner. I think I'm concluding that one sets the fuel flow to pick the horsepower desired, and then adjusts the MP to get the temperature desired (within reason). I thought 17.5 LOP would be about 75% power. So I went ROP and reduced MP until i got the same IAS as the LOP runs above. It took 27" MAP and 20 GPH to match the IAS, which I think is about 65% power (don't know why it isn't 75%...) -isaac N7842K ES-P ------=_Part_266532_683472257.1255753606895 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable <= div style=3D'font-family: Arial; font-size: 12pt; color: #000000'>In the or= iginal email, i asked what MP one should use when running LOP. George= Braly suggested i go out and find out for myself. So I did.

H= ere are two runs, both LOP at 2500 RPM and 17.5 GPH lean of peak:

30= " MAP
EGT 1558 1558 1576 1563 1528 1= 484
CHT 330 328 332 328 340 324
T= IT 1593 / 1634

31.6 MAP
EGT 1542 1544 1556 = ; 1540 1514 1472
CHT 326 322 326 324= 326 314
TIT 1578 / 1611

The IAS in both cases was th= e same, so the horsepower must have been the same. As one can see, hi= gher MP means cooler temperatures. Which makes sense, since the mixtu= re is leaner. I think I'm concluding that one sets the fuel flow to p= ick the horsepower desired, and then adjusts the MP to get the temperature = desired (within reason).

I thought 17.5 LOP would be about 75% power= . So I went ROP and reduced MP until i got the same IAS as the LOP ru= ns above. It took 27" MAP and 20 GPH to match the IAS, which I think = is about 65% power (don't know why it isn't 75%...)

-isaac
N7842K= ES-P

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