Mailing List flyrotary@lancaironline.net Message #15045
From: <kenpowell@comcast.net>
Subject: Re: [FlyRotary] Oil cooler baffles
Date: Mon, 10 Jan 2005 18:40:18 +0000
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
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)
 
 
 
 
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