Return-Path: Sender: (Marvin Kaye) To: lml Date: Sun, 18 Aug 2002 14:43:18 -0400 Message-ID: X-Original-Return-Path: Received: from smtprelay3.dc3.adelphia.net ([24.50.78.6] verified) by logan.com (CommuniGate Pro SMTP 4.0b6) with ESMTP id 1690403 for lml@lancaironline.net; Sun, 18 Aug 2002 10:31:06 -0400 Received: from worldwinds ([207.175.254.66]) by smtprelay3.dc3.adelphia.net (Netscape Messaging Server 4.15) with SMTP id H11MZT03.V0D for ; Sun, 18 Aug 2002 10:31:05 -0400 From: "Gary Casey" X-Original-To: "lancair list" Subject: leaning during climb X-Original-Date: Sun, 18 Aug 2002 07:29:48 -0700 X-Original-Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 <> I think you meant "fully closed." Yes the fuel control, even though it is not altitude compensated, thinks it is at a constant altitude if the manifold pressure is constant. There will be a slight leaning effect with climb as the back pressure drops, making the volumetric efficiency of the engine increase slightly with increasing altitude. Certainly at higher-than-cruise manifold pressures you don't want to tinker with the mixture, but at cruise manifold pressure I don't see any reason not to lean to a cruise condition. The engine doesn't know whether you are climbing or cruising - except for cooling and I don't think cooling would be worse in a low-altitude climb that it would be at a 25,000 foot cruise condition. Again, I don't have any IV-P experience. Gary Casey