X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [65.54.250.89] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 5.0.9) with ESMTP id 1110653 for flyrotary@lancaironline.net; Fri, 12 May 2006 11:42:59 -0400 Received-SPF: pass receiver=logan.com; client-ip=65.54.250.89; envelope-from=lors01@msn.com Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Fri, 12 May 2006 08:42:11 -0700 Message-ID: Received: from 4.171.150.238 by BAY115-DAV17.phx.gbl with DAV; Fri, 12 May 2006 15:42:08 +0000 X-Originating-IP: [4.171.150.238] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: oil cooling issues Date: Fri, 12 May 2006 11:42:02 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00BD_01C675B9.1615E110" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MimeOLE: Produced By MSN MimeOLE V9.20.0026.0800 Seal-Send-Time: Fri, 12 May 2006 11:42:02 -0400 X-OriginalArrivalTime: 12 May 2006 15:42:11.0988 (UTC) FILETIME=[A2B74D40:01C675DA] This is a multi-part message in MIME format. ------=_NextPart_000_00BD_01C675B9.1615E110 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message ----- Original Message -----=20 From: Al Gietzen=20 To: Rotary motors in aircraft=20 Sent: Friday, May 12, 2006 10:41 AM Subject: [FlyRotary] Re: oil cooling issues I have seen 260 F. many times, and I consider that normal during climb and taxi. I also use Mobil One Synthetic oil, to tolerate the heat. During cruise it will stabilize at 220F. =20 You need to get the oil above 220 F, to evaporate the moisture anyway. = Hi George, The "standard" (closest we have to one) for measuring oil temp is to = measure it as it returns to the engine, after the cooler. According to = Racing Beat, this temp should never exceed 210 F. Lot's of folks have = exceeded this for short periods, up to 240 F or so, and have had no = problems, but it's not something you really want to keep doing. =20 As I understand it, the issue is not the breakdown of the oil, but the = melting of the rotor bearings. =20 Hum-m. I was under the impression that the limiting factor side seal = O-rings. I've had the oil temp (after cooler) up to 220 -225 a few times for = very short periods on the ground. With no effective air flow through = the cooler, the before-cooler temp was only 3-4 degrees higher. It's a = different issue when running at high power where before-cooler temps may = be 30-50 degrees higher. Al That is my impression as well. Auto racing is another matter. They = are stressing the rotor bearings a lot more than we are (mainly due to = RPM) so that is probably the weak link in their use.=20 Your numbers for pre/post oil cooler temps are what I am seeing when = in-flight, I.e. 180 after the cooler =3D 220 - 230 in the pan. This is = a valuable number with which to judge oil cooler effectiveness. If you = don't get this much delta or more, your cooler is too small or airflow = too little. =20 Tracy (still can't figure out why I can't change text color after = Al's stuff) ------=_NextPart_000_00BD_01C675B9.1615E110 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
 
----- Original Message -----
From: Al Gietzen
To: Rotary motors in = aircraft
Sent: Friday, May 12, 2006 = 10:41 AM
Subject: [FlyRotary] Re: oil = cooling=20 issues

I have seen 260 F. many = times, and I=20 consider that normal during climb
and taxi.  I also use Mobil = One=20 Synthetic oil, to tolerate the heat.
During cruise it will = stabilize at=20 220F. 

You need to get the oil above 220 F, to evaporate = the=20 moisture anyway. 

 

Hi George,

 

The=20 "standard" (closest we have to one) for measuring oil temp is to = measure it as=20 it returns to the engine, after the cooler.  According to Racing = Beat,=20 this temp should never exceed 210 F.  Lot's of folks have = exceeded this=20 for short periods, up to 240 F or so, and have had no problems, but = it's not=20 something you really want to keep = doing.  

 

As I=20 understand it, the issue is not the breakdown of the oil, but the = melting=20 of the rotor bearings.

 =20

Hum-m.  I was=20 under the impression that the limiting factor side seal=20 O-rings.

 

I=92ve = had the oil=20 temp (after cooler) up to 220 -225 a few times for very short periods = on the=20 ground.  With no effective air flow through the cooler, the = before-cooler=20 temp was only 3-4 degrees higher.  It=92s a different issue when = running at=20 high power where before-cooler temps may be 30-50 degrees=20 higher.

 

Al

 

That is = my=20 impression as well.  Auto racing is another matter.  They = are=20 stressing the rotor bearings a lot more than we are (mainly due to = RPM) so=20 that is probably the weak link in their = use. 

 

 Your numbers=20 for pre/post oil cooler temps are what I am seeing when in-flight, = I.e. 180=20 after the cooler =3D 220 - 230 in the pan.   This is a = valuable number=20 with which to judge oil cooler effectiveness.   If you don't = get=20 this much delta or more, your cooler is too small or airflow too=20 little.  

 

Tracy  (still=20 can't figure out why I can't change text color after Al's=20 stuff)

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