Return-Path: Received: from hpamgaab.compuserve.com ([149.174.217.153]) by truman.olsusa.com (Post.Office MTA v3.5.1 release 219 ID# 0-52269U2500L250S0V35) with ESMTP id com for ; Tue, 9 Mar 1999 23:57:32 -0500 Received: (from mailgate@localhost) by hpamgaab.compuserve.com (8.8.8/8.8.8/HP-1.0) id XAA22260 for lancair.list@olsusa.com; Tue, 9 Mar 1999 23:59:29 -0500 (EST) Date: Tue, 9 Mar 1999 23:58:57 -0500 From: Lynda Frantz Subject: Oil Coolers/Engine cowling Sender: Lynda Frantz To: "INTERNET:lancair.list@olsusa.com" Message-ID: <199903092359_MC2-6D64-BA8@compuserve.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Disposition: inline X-Mailing-List: lancair.list@olsusa.com <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> I've never figured out why some folks put oil cooler doors or other movable devices on their aircraft in an attempt to control the oil temperature. My IO-360 has a vernitherm that meters the oil to the cooler to maintain the proper temperature and came standard with the engine. If the oil were too cool , the vernitherm would meter less oil to the cooler. Shutting off the air supply to the oil cooler would create less drag however. So, perhaps these doors should be called oil cooler drag reduction doors rather than oil temperature control doors. Am I missing something here? I selected an oil cooler known to be of adequate size. I sized the oil cooling air inlet NACA scoop so that the inlet area matched the SCAT tubing cross sectional area. The NACA scoop inlet area is the depth of the scoop times the width not the area of the cutout. It apparently works good as I have oil temps that are correct in all flight conditions. I found the engine cowling to be the most challenging component to fit to the aircraft. Although nobody wants to spend the money on an engine until absolutely necessary, I feel that you need to have your engine hung prior to fitting the engine cowl. I borrowed a prop just like the one I later bought and made a plywood disk that defined exactly where the back most plane of the prop spinner would be and cut to the proper diameter. This disk was bolted to the engine crank flange with the proper forward/aft spacing. The plywood disk was used as the clamping fixture to align the forward upper and lower cowl. Don't know how I could have done it any other way. Jim Frantz Lancair Network News