Return-Path: Received: from smtp5.gateway.net ([208.230.117.249]) by truman.olsusa.com (Post.Office MTA v3.5.1 release 219 ID# 0-64832U3500L350S0V35) with ESMTP id com for ; Mon, 21 Feb 2000 04:27:57 -0500 Received: from oemcomputer (1Cust108.tnt1.coeur-dalene.id.da.uu.net [63.27.107.108]) by smtp5.gateway.net (8.9.3/8.9.3) with SMTP id EAA13926 for ; Mon, 21 Feb 2000 04:33:22 -0500 (EST) Message-ID: <001101bf7c4f$7f62b860$6c6b1b3f@oemcomputer> Reply-To: "dfs" From: "dfs" To: "Lancair List" Subject: Reliability Date: Mon, 21 Feb 2000 01:37:52 -0800 X-Mailing-List: lancair.list@olsusa.com Mime-Version: 1.0 <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> Quite a number of our aircraft engines are designed (that is, via the carburetor or injection system) to substantially enrich the mixture in the last several percent of throttle advancement to provide additional fuel flow for cooling during full throttle operation. Pull the power back on take-off to below the point where this enrichment takes effect and you are increasing the thermal stress on combustion chamber components like piston crowns, exhaust valves and cylinder heads. In many of the high power engines we use in our Lancairs, the detonation margins, even with leaded fuel, is probably quite small and the enrichment feature at take-off power helps keep that under control. That all said, everyone should use the power setting methods they are comfortable with. I for one, however, will try to use aircraft engines I fly behind in the manner for which they were designed. Concerning full-power run-ups, anyone who can accomplish that must have an anchor out! Even with my little O-235, with the brakes locked, my airplane will start sliding forward at around 2200 - 2300 RPM. Next time at Redmond, I'd like to see that demonstrated! Dan Schaefer >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> LML website: http://www.olsusa.com/Users/Mkaye/maillist.html Builders' Bookstore: http://www.buildersbooks.com/lancair Please send your photos and drawings to marvkaye@olsusa.com. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>