Return-Path: Sender: (Marvin Kaye) To: flyrotary Date: Fri, 30 May 2003 11:32:32 -0400 Message-ID: X-Original-Return-Path: Received: from BAY0-SMTP02.adinternal.hotmail.com ([65.54.241.109] verified) by logan.com (CommuniGate Pro SMTP 4.1b6) with ESMTP id 2368639 for flyrotary@lancaironline.net; Fri, 30 May 2003 10:38:09 -0400 X-Originating-IP: [68.7.218.110] X-Originating-Email: [alventures@msn.com] Received: from BigAl ([68.7.218.110]) by BAY0-SMTP02.adinternal.hotmail.com with Microsoft SMTPSVC(5.0.2195.5600); Fri, 30 May 2003 07:38:08 -0700 Reply-To: From: "Al Gietzen" X-Original-To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: oil return location? X-Original-Date: Fri, 30 May 2003 07:38:32 -0700 Organization: ALVentures X-Original-Message-ID: <000e01c326b9$28480680$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000F_01C3267E.7BE92E80" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4024 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 In-reply-to: Importance: Normal X-Original-Return-Path: alventures@email.msn.com X-OriginalArrivalTime: 30 May 2003 14:38:08.0423 (UTC) FILETIME=[16775370:01C326B9] This is a multi-part message in MIME format. ------=_NextPart_000_000F_01C3267E.7BE92E80 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit I know that Tracy doesn't have any concrete proof that oil shouldn't be returned below the oil level, and logically it shouldn't make a great bit of difference, but I do agree with him here and think it's worth the effort to install a return port above the oil. With the return below the oil level in the pan, obviously the pan oil will back up into the drain line. I think Tracy made the key point. If the oil is from the re-drive is "frothy" (which it likely is) it will "float" at the interface with the clear oil and back up the drain line; in other words, not drain. It will only drain at a rate at which the oil and the entrained air separate; which in a tube could be very slow. A small amount of pressure would push it through, so it is not going to "blow" a seal, but oil backed up into the drive is likely to result in some seal leakage, as well as possible overheating of the oil. So it seems clear - return to a place above the pan oil level, and as best you can, maintain a positive slope in the line from the drive drain port to the drain outlet. Al ------=_NextPart_000_000F_01C3267E.7BE92E80 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable RE: [FlyRotary] Re: oil return location?

    I know that = Tracy doesn't have any concrete proof that oil shouldn't be returned below the = oil level, and logically it shouldn't make a great bit of difference, but I = do agree with him here and think it's worth the effort to install a return = port above the oil.

 

With the return below the oil = level in the pan, obviously the pan oil will back up into the drain line.  I = think Tracy made the key = point.  If the oil is from the re-drive is “frothy” (which it likely = is) it will “float” at the interface with the clear oil and back up = the drain line; in other words, not drain.  It will only drain at a = rate at which the oil and the entrained air separate; which in a tube could be = very slow.  A small amount of pressure would push it through, so it is = not going to “blow” a seal, but oil backed up into the drive is = likely to result in some seal leakage, as well as possible overheating of the = oil.

 

So it seems clear – return = to a place above the pan oil level, and as best you can, maintain a positive = slope in the line from the drive drain port to the drain outlet.  =  

 

Al

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