Return-Path: Received: from smtp105.mail.sc5.yahoo.com ([66.163.169.225] verified) by logan.com (CommuniGate Pro SMTP 4.2.8) with SMTP id 602252 for flyrotary@lancaironline.net; Mon, 10 Jan 2005 15:30:02 -0500 Received-SPF: none receiver=logan.com; client-ip=66.163.169.225; envelope-from=prvt_pilot@yahoo.com Received: from unknown (HELO stevehome) (prvt?pilot@24.136.229.34 with login) by smtp105.mail.sc5.yahoo.com with SMTP; 10 Jan 2005 20:29:46 -0000 Reply-To: From: "Steve Brooks" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Oil cooler baffles Date: Mon, 10 Jan 2005 15:29:48 -0500 Message-ID: <006801c4f753$21e07180$6b01a8c0@workgroup.com> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0069_01C4F729.390A6980" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook CWS, Build 9.0.6604 (9.0.2911.0) In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1441 Importance: Normal This is a multi-part message in MIME format. ------=_NextPart_000_0069_01C4F729.390A6980 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit MessageJohn, Given the nature of how a NACA scoop works, I don't see how you would have any air near the velocity to bend fins on the oil cooler. There must be some other explanation. I don't know how the 3rd gen cooler are, but the fins on a 2nd gen cooler aren't bent nearly as easily as those on a radiator. The oil cooler is fairly stout, not that you can't bend them. Could they have been bumped when the engine was removed/reinstalled ? Glad you're back in the air though. I'm hoping to make a trip to South Carolina this weekend, depending on the weather, to put some time on mine. Steve Brooks -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]On Behalf Of John Slade Sent: Monday, January 10, 2005 1:31 PM To: Rotary motors in aircraft Subject: [FlyRotary] Oil cooler baffles 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_000_0069_01C4F729.390A6980 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
John,
Given=20 the nature of how a NACA scoop works, I don't see how you would have any = air=20 near the velocity to bend fins on the oil cooler.  There must be = some other=20 explanation.
 
I=20 don't know how the 3rd gen cooler are, but the fins on a 2nd gen = cooler=20 aren't bent nearly as easily as those on a radiator.  The oil = cooler is=20 fairly stout, not that you can't bend them.
 
Could=20 they have been bumped when the engine was removed/reinstalled=20 ?
 
Glad=20 you're back in the air though.  I'm hoping to make a trip to South = Carolina=20 this weekend, depending on the weather, to put some time on=20 mine.
 
Steve=20 Brooks
 
 =20
-----Original Message-----
From: Rotary motors in = aircraft=20 [mailto:flyrotary@lancaironline.net]On Behalf Of John=20 Slade
Sent: Monday, January 10, 2005 1:31 PM
To: = Rotary=20 motors in aircraft
Subject: [FlyRotary] Oil cooler=20 baffles

Rotarians,
First an admission:
A=20 couple of days ago I took off with the landing brake down. I only have = the=20 NACA scoop, so the engine was getting very little air. By the time I = was=20 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=20 engine seems no worse for the experience. Oil pressure is ok to good = and=20 static rpm is unchanged. I flew again today (landing brake up) and = temps were=20 tolerable, but higher than I used to have long ago, in hotter weather = before=20 the new turbo and the rebuild. 
 
Now the question:
Looking at my two stock 3rd = gen oil=20 coolers after landing I noticed something strange - most of = the thin=20 aluminum baffles between the oil channels are = all bent flat, blocking the air flow. Those that aren't bent = are=20 toward the lower edge of the cooler where airflow might well be less. = They're=20 all bent the same in an even pattern that would indicate to me = that this=20 was either done by one of those crop circle guys on his day off, of = the high=20 pressure air from the scoop hitting the coolers at an angle.=20
 
Has=20 anyone else seen this? I know I can "comb" the aluminum straight = again, but=20 will it just happen again?
Should put a baffle in the air stream to angle the air=20 somehow?
 
John=20 (baffled)
 
 
 
 
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