Return-Path: Received: from sccrmhc11.comcast.net ([204.127.202.55] verified) by logan.com (CommuniGate Pro SMTP 4.2.8) with ESMTP id 602145 for flyrotary@lancaironline.net; Mon, 10 Jan 2005 13:40:36 -0500 Received-SPF: none receiver=logan.com; client-ip=204.127.202.55; envelope-from=kenpowell@comcast.net Received: from 204.127.205.142 (unknown[204.127.205.160](misconfigured sender)) by comcast.net (sccrmhc11) with SMTP id <20050110184020011003ecnte>; Mon, 10 Jan 2005 18:40:20 +0000 Received: from [166.102.160.133] by 204.127.205.142; Mon, 10 Jan 2005 18:40:18 +0000 From: kenpowell@comcast.net To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Oil cooler baffles Date: Mon, 10 Jan 2005 18:40:18 +0000 Message-Id: <011020051840.16602.41E2CC10000961DA000040DA220700295304040A99019F020A05@comcast.net> X-Mailer: AT&T Message Center Version 1 (Dec 17 2004) X-Authenticated-Sender: a2VucG93ZWxsQGNvbWNhc3QubmV0 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="NextPart_Webmail_9m3u9jl4l_16602_1105382418_0" --NextPart_Webmail_9m3u9jl4l_16602_1105382418_0 Content-Type: text/plain Content-Transfer-Encoding: 8bit Hi John, Comb the baffles out, immediately fly, then take a look upon landing. I just can't think of any other way to know for sure. This is the original 'scientific method'- craft an experiment and observe the results. The engineers have an advantage because they can usually get in the ballpark before they have to observe the reults of the experiment. Saves a bunch of money!!! Ken Powell Bryant, Arkansas 501-847-4721 -------------- Original message -------------- Rotarians, First an admission: A couple of days ago I took off with the landing brake down. I only have the NACA scoop, so the engine was getting very little air. By the time I was downwind the temps were outrageous. Coolant got to 270 and oil to 260. Needless to say I glided to a landing (on the runway) at idle. Thankfully the engine seems no worse for the experience. Oil pressure is ok to good and static rpm is unchanged. I flew again today (landing brake up) and temps were tolerable, but higher than I used to have long ago, in hotter weather before the new turbo and the rebuild. Now the question: Looking at my two stock 3rd gen oil coolers after landing I noticed something strange - most of the thin aluminum baffles between the oil channels are all bent flat, blocking the air flow. Those that aren't bent are toward the lower edge of the cooler where airflow might well be less. They're all bent the same in an even pattern that would indicate to me that this was either done by one of those crop circle guys on his day off, of the high pressure air from the scoop hitting the coolers at an angle. Has anyone else seen this? I know I can "comb" the aluminum straight again, but will it just happen again? Should put a baffle in the air stream to angle the air somehow? John (baffled) --NextPart_Webmail_9m3u9jl4l_16602_1105382418_0 Content-Type: text/html Content-Transfer-Encoding: 8bit

Hi John,

Comb the baffles out, immediately fly, then take a look upon landing. I just can't think of any other way to know for sure. This is the original 'scientific method'- craft an experiment and observe the results. The engineers have an advantage because they can usually get in the ballpark before they have to observe the reults of the experiment. Saves a bunch of money!!!

Ken Powell
Bryant, Arkansas
501-847-4721

-------------- Original message --------------

Rotarians,

First an admission:

A couple of days ago I took off with the landing brake down. I only have the NACA scoop, so the engine was getting very little air. By the time I was downwind the temps were outrageous. Coolant got to 270 and oil to 260. Needless to say I glided to a landing (on the runway) at idle. Thankfully the engine seems no worse for the experience. Oil pressure is ok to good and static rpm is unchanged. I flew again today (landing brake up) and temps were tolerable, but higher than I used to have long ago, in hotter weather before the new turbo and the rebuild.

Now the question:

Looking at my two stock 3rd gen oil coolers after landing I noticed something strange - most of the thin aluminum baffles between the oil channels are all bent flat, blocking the air flow. Those that aren't bent are toward the lower edge of the cooler where airflow might well be less. They're all bent the same in an even pattern that would indicate to me that this was either done by one of those crop circle guys on his day off, of the high pressure air from the scoop hitting the coolers at an angle.

Has anyone else seen this? I know I can "comb" the aluminum straight again, but will it just happen again?

Should put a baffle in the air stream to angle the air somehow?

John (baffled)

--NextPart_Webmail_9m3u9jl4l_16602_1105382418_0--