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 5.4.2) with ESMTP id 5171627 for flyrotary@lancaironline.net; Mon, 24 Oct 2011 22:37:04 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.78.142; envelope-from=Lehanover@aol.com Received: from mtaomg-da06.r1000.mx.aol.com (mtaomg-da06.r1000.mx.aol.com [172.29.51.142]) by imr-ma06.mx.aol.com (8.14.1/8.14.1) with ESMTP id p9P2aHok017768 for ; Mon, 24 Oct 2011 22:36:17 -0400 Received: from core-mod001c.r1000.mail.aol.com (core-mod001.r1000.mail.aol.com [172.29.196.1]) by mtaomg-da06.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 85F21E000081 for ; Mon, 24 Oct 2011 22:36:17 -0400 (EDT) From: Lehanover@aol.com Message-ID: <645b.75111cec.3bd77aa1@aol.com> Date: Mon, 24 Oct 2011 22:36:17 -0400 (EDT) Subject: Re: [FlyRotary] oil in the gearbox To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_645b.75111cec.3bd77aa1_boundary" X-Mailer: AOL 9.6 sub 5004 X-Originating-IP: [173.88.22.222] x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:468058048:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d338e4ea620a12117 --part1_645b.75111cec.3bd77aa1_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit I would not trust a standard Garlock style seal above 2 pounds. You can do better. You can install 2 half width Garlocks. You can install a 2 way seal that has lips facing in and out. You grease the void between the lips, so both seals live a long time and no dust can walk under the sealing lip (inside lip) and fail it. It is not tyipical for a properly installed seal to leak anything at all. The higher the leak pressure the more tightly the lip grips the shaft causing a short life . You can push the seal out of the hole with too much pressure. You can turn a lip seal inside out with too much pressure. Some seals have springs that assist the lip in gripping the shaft. These are used in very dynamic applications like gear boxes. Gear boxes should have close to zero pressure. Any pressure must be subtracted from the supply pressure, which is usually low to start with. Seals in aluminum tend to be too loose a fit at high temperature, and although there is seldom a problem with leakage I clamp Garlocks in place with 10-32 screws and small bent washers. You can also lay a bearing shim over the garlock and use flat washers. It looks better. Same for plain bearings, like in tailshaft housings. Even with oil coolers a bushing will often spin up and hose the tailshaft casting. So I put a screw through them. You can add a very thin "O" ring in the bottom of the seal well that can seal against the chamfer on the outer corner of the seal, but you must clamp the seal in against this "O" ring for it to work. And as ghastly as it may seem, you can lay in a very small bead of non hardening Permatex sealant on top of that "O" ring. You need not tell anyone that you did this. There is no shame in using a seal in good condition over again. Just check to see that the lips are still flexible. In olden times when junk engines were raced every weekend I would shorten the spring on the rear seal of my rotary to keep the oil inside the engine that had so much blow by that we emptied the catch can back into the engine after each session. Lynn E. Hanover In a message dated 10/24/2011 9:09:00 P.M. Paraguay Daylight Time, echristley@nc.rr.com writes: The question I have is do I need to replace the front and rear oil seals. I pressed the front oil seal back in, and even added a couple of retainers, as Lynn has suggested; but, should I replace it with new one, even if it doesn't leak? I put a rubber hose over the oil inlet, and blew into it. I could hear it bubble out of the rear seal when I covered the oil outlet. How much pressure should those rubber seals be expected to contain? --part1_645b.75111cec.3bd77aa1_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
I would not trust a standard Garlock style seal above 2 pounds. You ca= n do=20 better.
 
You can install 2 half width Garlocks. You can install a 2 way seal th= at=20 has lips facing in and out. You grease the void between the lips, so both s= eals=20 live a long time and no dust can walk under the sealing lip (inside lip) an= d=20 fail it. It is not tyipical for a properly installed seal to leak anything = at=20 all. The higher the leak pressure the more tightly the lip grips the shaft= =20 causing a short life
 
. You can push the seal out of the hole with too much pressure. You ca= n=20 turn a lip seal inside out with too much pressure. Some seals have springs = that=20 assist the lip in gripping the shaft. These are used in very dynamic=20 applications like gear boxes.
 
Gear boxes should have close to zero pressure. Any pressure must be=20 subtracted from the supply pressure, which is usually low to start with.
 
Seals in aluminum tend to be too loose a fit at high temperature, and= =20 although there is seldom a problem with leakage I clamp Garlocks in place w= ith=20 10-32 screws and small bent washers. You can also lay a bearing shim over t= he=20 garlock and use flat washers. It looks better. Same for plain bearings, lik= e in=20 tailshaft housings. Even with oil coolers a bushing will often spin up and = hose=20 the tailshaft casting. So I put a screw through them.
 
You can add a very thin "O" ring in the bottom of the seal well that c= an=20 seal against the chamfer on the outer corner of the seal, but you must clam= p the=20 seal in against this "O" ring
for it to work.
 
And as ghastly as it may seem, you can lay in a very small bead o= f non=20 hardening Permatex
sealant on top of that "O" ring. You need not tell anyone that you did= =20 this.
 
There is no shame in using a seal in good condition over again. Just c= heck=20 to see that the lips are still flexible.
 
In olden times when junk engines were raced every weekend I would shor= ten=20 the spring on the rear seal of my rotary to keep the oil inside the engine = that=20 had so much blow by that we emptied the catch can back into the engine afte= r=20 each session.
 
Lynn E. Hanover
 
In a message dated 10/24/2011 9:09:00 P.M. Paraguay Daylight Time,=20 echristley@nc.rr.com writes:
= The=20 question I have is do I need to replace the front and rear oil=20
 
=
seals.  I pressed the front oil seal back in, and e= ven=20 added a couple of
retainers, as Lynn has suggested;  but, should= I=20 replace it with new
one, even if it doesn't leak?  I put a rubbe= r=20 hose over the oil inlet,
and blew into it.  I could hear it bubb= le=20 out of the rear seal when I
covered the oil outlet.  How much=20 pressure should those rubber seals be
expected to=20 contain?
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