X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from omr-d04.mx.aol.com ([205.188.109.201] verified) by logan.com (CommuniGate Pro SMTP 6.0.5) with ESMTP id 6267102 for flyrotary@lancaironline.net; Sun, 12 May 2013 22:42:47 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.109.201; envelope-from=Lehanover@aol.com Received: from mtaomg-ma02.r1000.mx.aol.com (mtaomg-ma02.r1000.mx.aol.com [172.29.41.9]) by omr-d04.mx.aol.com (Outbound Mail Relay) with ESMTP id 3DD0A700000AB for ; Sun, 12 May 2013 22:42:12 -0400 (EDT) Received: from core-mob004c.r1000.mail.aol.com (core-mob004.r1000.mail.aol.com [172.29.194.205]) by mtaomg-ma02.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 0FF59E000085 for ; Sun, 12 May 2013 22:42:12 -0400 (EDT) From: Lehanover@aol.com Full-name: Lehanover Message-ID: <13e17a.5f5767c9.3ec1ad03@aol.com> Date: Sun, 12 May 2013 22:42:11 -0400 (EDT) Subject: Re: [FlyRotary] Re: damn front o-ring again revisited again again again......... To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_13e17a.5f5767c9.3ec1ad03_boundary" X-Mailer: AOL 9.7 sub 55 X-Originating-IP: [173.88.28.139] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20121107; t=1368412932; bh=I2JBJ8d8i3nNVc5V2GdqxMiBlDFyCDBXr85AtxWJAyA=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=Gh2TQxoVhViIBifYN0JAs9miClgqxi2ae2Jcuk1rxXXp5Qn1peQ4nZV95B8LtJcJJ 22Uzns9qZvKp5bhrOYA7tGbH1LugFiAYQKsrFnXWxxmNHZsZr847YYwAKCBN6yvIQS wde8gysDa29H8fflZlhH+sCK5lvzh6Mdp3QRp+rI= X-AOL-SCOLL-SCORE: 0:2:399134592:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d29095190530415d6 --part1_13e17a.5f5767c9.3ec1ad03_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit The front cover relief is set at 140 pounds to protect the oil cooler. But not the "O" ring junction. The pressure relief in the rear iron controls all oil pressure. However since this valve is at the very end of the oiling system, all locations ahead of this valve get a higher oil pressure than the relief valve setting. Where the relief valve is in the pump, all locations after the pump receive a pressure that is lower than the pump relief pressure setting. So, the Mazda has an advantage in that regard. But the lowest pressure is furthest from the "O" ring junction. So when oil is cold, or cool, the pressure may be quite a bit higher than the pop setting of the valve. The relief valve has some hysterisis and may move slowly to its pop pressure. This allows for a large over pressure between the valve and the oil pump. So, you have the pop pressure of the front relief valve and the "O" ring failing in order to save the oil cooler. Reving the engine quickly from idle, or from one RPM to a higher RPM may produce this effect. But once the engine is running and or the oil is warm the valve is sitting in its popped position and leaking oil to maintain its set pressure. So movement to control a surge in flow will be slight and fast as the vent is a series of round holes. A hat section device with a flange to fit the land area about .050" or more thick with a thin walled tube to fit into the front cover gallery or even a counter bore in the gallery to fit a slightly larger tube and maintain the original gallery diameter. There will be no "O" ring to blow out. A flange of .050" or even thicker would overcome the cover from being pushed forward from shear preload. Some leakage might occur but would be minimal. Another approach would be to trim down a thick "O"ring seal washer for this job. Washers (usually aluminum) with an "O" ring molded around the hole. The key will be to have a thick enough spacer (flange) to stop the cover from moving off of the land area. After May I can work on this problem. Perhaps a test rig to measure leakage at such a fix. Lynn E. Hanover In a message dated 5/12/2013 12:08:26 P.M. Eastern Daylight Time, bartrim@gmail.com writes: Hi Lynn; My oil pump outlet is now in the front iron where there was previously a brass plug. From there it flows through a remote mounted oil filter then on t o the oil cooler before returning to the engine through the original point in the rear iron (although I did change that fitting). The front cover still contains one of the oil relief/pressure control valves while the main one is still located in the rear iron. My memory is beginning to fail as I recall that one of these is a oil pressure control valve and the other is a safety relief valve, but can't remember the details at this point. Todd Bartrim On Sun, May 12, 2013 at 3:05 AM, <_Lehanover@aol.com_ (mailto:Lehanover@aol.com) > wrote: Please draw us a flow diagram of your oiling system. So, the front cover outlet only supplies oil to the banjo fitting in the rear iron and then only to the relief valve? Lynn E. Hanover In a message dated 5/11/2013 9:30:27 P.M. Eastern Daylight Time, _bartrim@gmail.com_ (mailto:bartrim@gmail.com) writes: Yes. I did this long ago, before first flight. Never had any problem with it. --part1_13e17a.5f5767c9.3ec1ad03_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
The front cover relief is set at 140 pounds to protect the oil cooler.= But=20 not the "O" ring junction. The pressure relief in the rear iron controls al= l oil=20 pressure.
 
However since this valve is at the very end of the oiling system, all= =20 locations ahead of this valve get a higher oil pressure than the relief val= ve=20 setting. Where the relief valve is in the pump, all locations after the pum= p=20 receive a pressure that is lower than the pump relief pressure setting. So,= the=20 Mazda has an advantage in that regard.
 
But the lowest pressure is furthest from the "O" ring junction. So whe= n oil=20 is cold, or cool, the pressure may be quite a bit higher than the pop setti= ng of=20 the valve. The relief valve has some hysterisis and may move slow= ly to=20 its pop pressure. This allows for a large over pressure between the valve a= nd=20 the oil pump. So, you have the pop pressure of the front relief valve and t= he=20 "O" ring failing in order to save the oil cooler.
 
Reving the engine quickly from idle, or from one RPM to a higher RPM
may produce this effect. But once the engine is running and or the oil= is=20 warm the valve is sitting in its popped position and leaking oil to=20 maintain its set pressure. So movement to control a surge in flow will be s= light=20 and fast as the vent is a series of round holes.
 
A hat section device with a flange to fit the land area about .050" or= more=20 thick with a thin walled tube to fit into the front cover gallery or even a= =20 counter bore in the gallery to fit a slightly larger tube and maintain the= =20 original gallery diameter. There will be no "O" ring to blow out. A flange = of=20 .050" or even thicker would overcome the cover from being pushed forward fr= om=20 shear preload. Some leakage might occur but would be minimal. Another appro= ach=20 would be to trim down a thick "O"ring seal washer for this job. Washers (us= ually=20 aluminum) with an "O" ring molded around the hole.
 
The key will be to have a thick enough spacer (flange) to stop the cov= er=20 from moving off of the land area. After May I can work on this problem.
Perhaps a test rig to measure leakage at such a fix.
 
Lynn E. Hanover
 
 
In a message dated 5/12/2013 12:08:26 P.M. Eastern Daylight Time,=20 bartrim@gmail.com writes:
=
Hi Lynn;=20
My oil pump outlet is now in the front iron where there was previous= ly a=20 brass plug. From there it flows through a remote mounted oil filter then = on to=20 the oil cooler before returning to the engine through the original point = in=20 the rear iron (although I did change that fitting).
The front cover still contains one of the oil relief/pressure contro= l=20 valves while the main one is still located in the rear iron. My memory is= =20 beginning to fail as I recall that one of these is a oil pressure control= =20 valve and the other is a safety relief valve, but can't remembe= r the=20 details at this point.

Todd Bartrim


On Sun, May 12, 2013 at 3:05 AM, <Lehanover@aol.com> wrote:
Please draw us a flow diagram of your oiling system. So, the front= =20 cover outlet only supplies oil to the banjo fitting in the rear iron an= d=20 then only to the relief valve?
 
Lynn E. Hanover
 
In a message dated 5/11/2013 9:30:27 P.M. Eastern Daylight Time, <= A=20 title=3Dmailto:bartrim@gmail.com href=3D"mailto:bartrim@gmail.com"=20 target=3D_blank>bartrim@gmail.com writes:
Yes. I did this long ago, before first flight. Never had any pro= blem=20 with=20 it.

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