X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fmailhost02.isp.att.net ([207.115.11.52] verified) by logan.com (CommuniGate Pro SMTP 5.2c1) with ESMTP id 2493095 for flyrotary@lancaironline.net; Sat, 17 Nov 2007 10:23:56 -0500 Received-SPF: none receiver=logan.com; client-ip=207.115.11.52; envelope-from=rusty@radrotary.com Received: from rad (adsl-065-006-194-009.sip.pns.bellsouth.net[65.6.194.9]) by bellsouth.net (frfwmhc02) with SMTP id <20071117152317H02000dkfle>; Sat, 17 Nov 2007 15:23:17 +0000 X-Originating-IP: [65.6.194.9] From: "Russell Duffy" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Pulsation Fatique was [FlyRotary] Re: Harrison cores Date: Sat, 17 Nov 2007 09:23:17 -0600 Message-ID: <000001c8292d$c7cbaba0$6c01a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C828FB.7D313BA0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6822 Importance: Normal Thread-Index: AcgnwWBtqYhF583hSSOvbmnNTxppRwBa2NYg In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C828FB.7D313BA0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable One thing you may want to check on (Rusty are you still on?) is that = while the Harrison GM cores can take a lot of pressure, the pressure = pulsations by such things as positive displacement oil pump could possible fatigue the metal. While I know of no conclusive proof of this happening, there has been more than one failure of a Harrison GM core being used as an oil cooler. =20 =20 Hi Ed, =20 I'm still around, but haven't been following the list too closely. I = let the messages pile up, then delete anything that looks like it requires a thermodynamics degree, or debating skills :-) =20 =20 FWIW, I had two of these cores fail when using them as oil coolers. The first happened on the ground, and was just a small leak. That core had = been dented in shipping, so I assumed that was why it failed. The = replacement core (both were new, not salvage) worked perfectly until I made the = mistake of trying to make my first short cross country flight. On the way back, = it split at one of the tank seams, and the rest is history. I would never consider using one of these as an oil cooler again. =20 =20 Rusty (selling gyro, waiting for RV-12, working on single rotor)=20 ------=_NextPart_000_0001_01C828FB.7D313BA0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message
One thing you may want to check on (Rusty are = you still=20 on?) is that while the Harrison GM cores can take a lot of pressure, the = pressure pulsations by such things as positive displacement oil pump = could=20 possible fatigue the metal.  While I know of no conclusive proof of = this=20 happening, there has been more than one failure of a Harrison GM core = being used=20 as an oil cooler.   
 
Hi=20 Ed,
 
I'm=20 still around, but haven't been following the list too closely.  I = let the=20 messages pile up, then delete anything that looks like it requires a=20 thermodynamics degree, or debating skills=20 :-)  
 
FWIW, I=20 had two of these cores fail when using them as oil coolers.  The = first=20 happened on the ground, and was just a small leak.  That core had = been=20 dented in shipping, so I assumed that was why it failed.  The = replacement=20 core (both were new, not salvage) worked perfectly until I made the = mistake=20 of trying to make my first short cross country flight.  On the = way=20 back, it split at one of the tank seams, and the rest is = history.  I=20 would never consider using one of these as an oil cooler=20 again.  
 
Rusty=20 (selling gyro, waiting for RV-12, working on single=20 rotor) 
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