X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-ma06.mx.aol.com ([64.12.78.142] verified) by logan.com (CommuniGate Pro SMTP 6.0.1) with ESMTP id 6068085 for flyrotary@lancaironline.net; Sun, 17 Feb 2013 07:35:59 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.78.142; envelope-from=Lehanover@aol.com Received: from mtaomg-da01.r1000.mx.aol.com (mtaomg-da01.r1000.mx.aol.com [172.29.51.137]) by imr-ma06.mx.aol.com (Outbound Mail Relay) with ESMTP id 09D991C000098 for ; Sun, 17 Feb 2013 07:35:25 -0500 (EST) Received: from core-mob004b.r1000.mail.aol.com (core-mob004.r1000.mail.aol.com [172.29.194.205]) by mtaomg-da01.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 66934E000085 for ; Sun, 17 Feb 2013 07:35:23 -0500 (EST) From: Lehanover@aol.com Full-name: Lehanover Message-ID: <5e41c.7754bdd8.3e52288b@aol.com> Date: Sun, 17 Feb 2013 07:35:23 -0500 (EST) Subject: Re: [FlyRotary] Re: That damn O-ring again! To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_5e41c.7754bdd8.3e52288b_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=1361104524; bh=Ioj3r9Lg1w9Qk7nmdcmtubw4ZMN6oQJ3I8qNE5oHs6Q=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=bSUQw85qB1LJjY4VfCtqKkvSHe/uUQQuDsS1H345nIO6Rcq6UhWo/87afRIsCqGFU XIkTxA2O8Ox61vDm1sRntHs+hEg8UJ3BwIE7CimEMlphyTkSHBBr2P1Gddsg2ehZh7 JduzfnLq1qIWuc4vVQOYIALWGUSDu4T+DVYJiWS8= X-AOL-SCOLL-SCORE: 0:2:489591584:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d33895120ce8b4962 --part1_5e41c.7754bdd8.3e52288b_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit The problem is that the front cover is very flexible and there is no fastener near this junction. (Thank you Mazda) On a cold start the oil pressure at this junction can far exceed the pop pressure of the stock pressure relief valve located at the base of the rear iron. On some models of front iron there is a relief valve just below this junction set at 140 pounds. This is to protect the oil cooler, which is a good idea but is too high a pressure to keep the junction from pushing open and releasing the "O" ring. The object of the thick glass reinforced white washer (probably Teflon or Nylon) fitted at this junction was to create added pressure between the aluminum and the cast iron. It's a spacer. If Mazda had left the aluminum tube .060" taller than the gasket surface Or installed a fastener close by, they would never have had this problem This was a Mazda fix for the problem that had some success. The washer took up some space and then a thicker "O" ring was installed to do the sealing. The washer might have done some sealing if oil had slipped past the "O" ring, but it could have been made of any sturdy material. Steel or aluminum. Later versions of the front cover gasket had extensions of hard paper that fit around the washer. (And did nothing). Later still a composition gasket with a stainless face replacing the washer. There was never an attempt to fix the cause. Just cheap gags to prevent the outcome. Your fix looks just fine. I would make the ID of the brass tube just a bit bigger and taper the ends for less drag. Oil goes through here at a fairly high rate. I have not seen how this was done on FD or Renesis engines. Lynn E. Hanover In a message dated 2/17/2013 5:57:16 A.M. Eastern Standard Time, msteitle@gmail.com writes: Todd, What happened to the counter-bore in the front iron? Did your model not have a counter-bore? It appears to have been filled in with Devcon (or JB)? The walls of the counter-bore are supposed to hold the o-ring in place and prevent it from being forced out under pressure. At least that's my understanding of how it works. From the pictures, it appears that the thick-wall bushing will be choking off much of your oil flow, possibly causing other problems (bearing failure). Mark S. On Sun, Feb 17, 2013 at 1:34 AM, Todd Bartrim <_bartrim@gmail.com_ (mailto:bartrim@gmail.com) > wrote: Hello All; It's been awhile since I last posted, though I've been reading almost every post to sort of keep up with the latest developments. The last time I flew I was seeing lower oil pressures around 35-40 psi, so I decided to pull the front cover the other day. I had previously had a complete O-ring failure so had done the recommended fix at the time. When I pulled it the other day, everything looked good but obviously wasn't. I recalled Chris having a repeat of this last fall so searched the archives and found a reference to him pushing a small cylinder in there. There was also a previous post where Lynn commented on somebody else's idea of a Teflon washer being a good idea. So I've decided to do both. Attached pics should show in better detail than I could explain. I've done a trial fit, but will await comments before I assemble with sealant. Todd Bartrim C-FSTB -- Homepage: _http://www.flyrotary.com/_ (http://www.flyrotary.com/) Archive and UnSub: _http://mail.lancaironline.net:81/lists/flyrotary/List.html_ (http://mail.lancaironline.net:81/lists/flyrotary/List.html) --part1_5e41c.7754bdd8.3e52288b_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
The problem is that the front cover is very flexible and there is no= =20 fastener near this junction. (Thank you Mazda)
On a cold start the oil pressure at this junction can far exceed the p= op=20 pressure of the stock pressure relief valve located at the base of the rear= =20 iron. On some models of front iron there is a relief valve just below this= =20 junction set at 140 pounds. This is to protect the oil cooler, which is a g= ood=20 idea but is too high a pressure to keep the junction from pushing open and= =20 releasing the "O" ring.  
 
The object of the thick glass reinforced white washer (probably Teflon= or=20 Nylon) fitted at this junction was to create added pressure between the alu= minum=20 and the cast iron. It's a spacer.
 
If Mazda had left the aluminum tube .060" taller than the gasket=20 surface  Or installed a fastener close by, they would never have had t= his=20 problem
 
This was a Mazda fix for the problem that had some success. The washer= took=20 up some space and then a thicker "O" ring was installed to do the sealing. = The=20 washer might have done some sealing if oil had slipped past the "O" ring, b= ut it=20 could have been made of any sturdy material. Steel or aluminum.
 
Later versions of the front cover gasket had extensions of hard paper = that=20 fit around the washer. (And did nothing). Later still a composition gasket = with=20 a stainless face replacing the washer. There was never an attempt to fix th= e=20 cause. Just cheap gags to prevent the outcome.
 
Your fix looks just fine. I would make the ID of the brass tube just a= bit=20 bigger and taper the ends for less drag. Oil goes through here at a fairly = high=20 rate.
 
I have not seen how this was done on FD or Renesis engines.
 
Lynn E. Hanover
 
In a message dated 2/17/2013 5:57:16 A.M. Eastern Standard Time,=20 msteitle@gmail.com writes:
= Todd, =20

What happened to the counter-bore in the front iron?  Did your = model=20 not have a counter-bore?  It appears to have been filled in with Dev= con=20 (or JB)?  The walls of the counter-bore are supposed to hold the o-r= ing=20 in place and prevent it from being forced out under pressure.  At le= ast=20 that's my understanding of how it works.  

From the pictures, it appears that the thick-wall bushing will be ch= oking=20 off much of your oil flow, possibly causing other problems (bearing=20 failure).

Mark S.

On Sun, Feb 17, 2013 at 1:34 AM, Todd Bartrim <bartrim@gmail.com> wrote:
Hello All;
It's been awhile since I last posted, though I've been= =20 reading almost every post to sort of keep up with the latest=20 developments.
    The last time I flew I was seeing lower oil pressure= s=20 around 35-40 psi, so I decided to pull the front cover the other day. I= had=20 previously had a complete O-ring failure so had done the recommended fi= x at=20 the time. When I pulled it the other day, everything looked good but=20 obviously wasn't. I recalled Chris having a repeat of this last fall so= =20 searched the archives and found a reference to him pushing a small cyli= nder=20 in there. There was also a previous post where Lynn commented on somebo= dy=20 else's idea of a Teflon washer being a good idea. So I've decided to do= =20 both. Attached pics should show in better detail than I could explain. = I've=20 done a trial fit, but will await comments before I assemble with=20 sealant.

Todd Bartrim

C-FSTB
--
Homepage:=20  http://www.flyrotary.com/
Archive and UnSub: &nb= sp; http://mail.lancaironline.net:81/lists/flyrotary/List.h= tml


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