X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 21 Aug 2011 14:09:47 -0400 Message-ID: X-Original-Return-Path: Received: from smtpauth05.prod.mesa1.secureserver.net ([64.202.165.99] verified) by logan.com (CommuniGate Pro SMTP 5.4.1) with SMTP id 5097773 for lml@lancaironline.net; Fri, 19 Aug 2011 15:15:51 -0400 Received-SPF: none receiver=logan.com; client-ip=64.202.165.99; envelope-from=jayph@fastairplane.net Received: (qmail 18825 invoked from network); 19 Aug 2011 19:15:15 -0000 Received: from unknown (174.126.244.48) by smtpauth05.prod.mesa1.secureserver.net (64.202.165.99) with ESMTP; 19 Aug 2011 19:15:15 -0000 Reply-To: From: "Jay Phillips" X-Original-To: "'Lancair Mailing List'" References: In-Reply-To: Subject: RE: [LML] Re: lHow do I run lean of peak? X-Original-Date: Fri, 19 Aug 2011 12:15:54 -0700 X-Original-Message-ID: <024d01cc5ea4$6b609140$4221b3c0$@net> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_024E_01CC5E69.BF01B940" X-Mailer: Microsoft Office Outlook 12.0 Content-Language: en-us Thread-Index: AcxejE0rDhFaThbbRwOXdzGeDhi7rwAFvrzw This is a multi-part message in MIME format. ------=_NextPart_000_024E_01CC5E69.BF01B940 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit The problem with this approach is that if your fuel flows are badly unbalanced you can reach the point of lean roughness in one cylinder while other(s) are in "the red box" (region of high compression pressures). To avoid the red box make sure power output is below 60-65%. The safest way to do this in a non-turbo aircraft is to climb high enough so that even with WOT (Wide Open Throttle) the reduced pressure limits engine power. In my Legacy with a IO-550N that is about 8500 feet. The other way to limit power is with the throttle. If you stay below 60-65% power you are out of the red box and thus can play with themixture to your heart's content. This is all simplified and filtered through my memory (a very dangerous thing to depend on). I continue to strongly recommend the Advanced Pilot Seminar class, either live or online. Of course, if you don't mind rebuilding expensive aircraft engines and making emergency deadstick landings, you can save the money you would otherwise spend on the class J Jay Phillips From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Gary Casey Sent: Friday, August 19, 2011 9:23 AM To: lml@lancaironline.net Subject: [LML] Re: lHow do I run lean of peak? Lots of excellent replies on the subject, but I might have a suggestion that will make it more comfortable to "get your feet in the water" initially. If you lean gradually while at a relatively high cruise power setting you are going to spend significant time in the "bad place" before you get LOP. I practiced a little with the "big pull" - not turning the mixture knob, but just pulling. Start at a runup power setting where you can't hurt anything and pull until the power drops off noticeably. If you listen carefully, the engine noise changes to a "smoother" or more "mellow" sound at the same time the power drops. That's what you are looking for. Now in the air do the same thing. Pretty soon you will be able to lean just by the sound and feel and get pretty close to the setting you want, hopefully without the passengers becoming alert :-). You can fine tune from there. Just what I did. YMMV Gary Casey ------=_NextPart_000_024E_01CC5E69.BF01B940 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

The problem with this approach is that if your fuel flows are badly = unbalanced you can reach the point of lean roughness in one cylinder = while other(s) are in “the red box” (region of high = compression pressures). To avoid the red box make sure power output is = below 60-65%. The safest way to do this in a non-turbo aircraft is to = climb high enough so that even with WOT (Wide Open Throttle) the reduced = pressure limits engine power. In my Legacy with a IO-550N that is about = 8500 feet. The other way to limit power is with the throttle. If you = stay below 60-65% power you are out of the red box and thus can play = with themixture to your heart’s content.

This is all simplified and filtered through my memory (a very = dangerous thing to depend on). I continue to strongly recommend the = Advanced Pilot Seminar class, either live or online. Of course, if you = don’t mind rebuilding expensive aircraft engines and making = emergency deadstick landings, you can save the money you would otherwise = spend on the class J

Jay Phillips

From:= = Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of = Gary Casey
Sent: Friday, August 19, 2011 9:23 = AM
To: lml@lancaironline.net
Subject: [LML] Re: lHow = do I run lean of peak?

Lots of excellent = replies on the subject, but I might have a suggestion that will make it = more comfortable to "get your feet in the water" initially. = If you lean gradually while at a relatively high cruise power = setting you are going to spend significant time in the "bad = place" before you get LOP. I practiced a little with the = "big pull" - not turning the mixture knob, but just pulling. = Start at a runup power setting where you can't hurt anything and = pull until the power drops off noticeably. If you listen = carefully, the engine noise changes to a "smoother" or more = "mellow" sound at the same time the power drops. That's = what you are looking for. Now in the air do the same thing. = Pretty soon you will be able to lean just by the sound and = feel and get pretty close to the setting you want, hopefully without the = passengers becoming alert :-). You can fine tune from = there.

Just what I did. = YMMV

Gary Casey

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