X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mtiwmhc13.worldnet.att.net ([204.127.131.117] verified) by logan.com (CommuniGate Pro SMTP 5.0c1) with ESMTP id 688390 for flyrotary@lancaironline.net; Wed, 31 Aug 2005 17:15:18 -0400 Received-SPF: none receiver=logan.com; client-ip=204.127.131.117; envelope-from=keltro@att.net Received: from 204.127.135.75 ([204.127.135.75]) by worldnet.att.net (mtiwmhc13) with SMTP id <2005083121142311300n3ap8e>; Wed, 31 Aug 2005 21:14:33 +0000 Received: from [209.247.222.95] by 204.127.135.75; Wed, 31 Aug 2005 21:14:22 +0000 From: keltro@att.net (Kelly Troyer) To: "Rotary motors in aircraft" Subject: Re: Rational for TES "O" Rings Date: Wed, 31 Aug 2005 21:14:22 +0000 Message-Id: <083120052114.17753.43161DAD000BAC63000045592160466648019D9B040A05@att.net> X-Mailer: AT&T Message Center Version 1 (Feb 14 2005) X-Authenticated-Sender: a2VsdHJvQGF0dC5uZXQ= MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="NextPart_Webmail_9m3u9jl4l_17753_1125522862_0" --NextPart_Webmail_9m3u9jl4l_17753_1125522862_0 Content-Type: text/plain Content-Transfer-Encoding: 8bit -------------- Original message from "Russell Duffy" <13brv3@bellsouth.net>: -------------- I am of the opinion (yet to be proven ) that the use of TES seals in the rotors may raise the critical temp for oil.......It is well known that the 13B is most efficient with oil temps in the 160 to 200 F range and that power suffers above these numbers........I do not advocate flying with oil temps above those numbers but most of us will struggle with oil temps as we sort out our oil cooling systems.........My hope is that the TES seals will provide a safety buffer for oil temp by preventing the rotor oil seals from going away with short periods of over temp during test flying......The same can be said for the inner coolent seal as well with the outer seal probably not a real problem (but they are less expensive than stock)........ Kelly Troyer Hi Kelly, I can't fault any of the above logic. When this discussion first came up, I was thinking only of the coolant o-rings, and never once considered that TES could be used for the oil seals. Assuming they work as well as they should, I agree that it might help some to use them. I can't find the message now, but I believe Lynn or Leon told us that the first failure from overheating the oil would be the soft material on the bearings. Can someone confirm this? What is the first thing to fail when the oil temp gets too high? Cheers, Rusty (RV-3 tentatively sold) Granted Rusty...... No seal material will save you when things get hot enough to melt the bearing material !! We are talking oil temps probably no more than the mid to high two hundred F range where the Viton seals start to break down and harden.......IMHO Kelly --NextPart_Webmail_9m3u9jl4l_17753_1125522862_0 Content-Type: text/html Content-Transfer-Encoding: 8bit

-------------- Original message from "Russell Duffy" <13brv3@bellsouth.net>: --------------

I am of the opinion (yet to be proven ) that the use of TES seals in the

rotors may raise the critical temp for oil.......It is well known that the 13B

is most efficient with oil temps in the 160 to 200 F range and that power

suffers above these numbers........I do not advocate flying with oil temps

above those numbers but most of us will struggle with oil temps as we

sort out our oil cooling systems.........My hope is that the TES seals will

provide a safety buffer for oil temp by preventing the rotor oil seals from

going away with short periods of over temp during test flying......The

same can be said for the inner coolent seal as well with the outer seal

probably not a real problem (but they are less expensive than stock)........

Kelly Troyer

Hi Kelly,

I can't fault any of the above logic. When this discussion first came up, I was thinking only of the coolant o-rings, and never once considered that TES could be used for the oil seals. Assuming they work as well as they should, I agree that it might help some to use them.

I can't find the message now, but I believe Lynn or Leon told us that the first failure from overheating the oil would be the soft material on the bearings. Can someone confirm this? What is the first thing to fail when the oil temp gets too high?

Cheers,

Rusty (RV-3 tentatively sold)

Granted Rusty...... No seal material will save you when things get hot enough

to melt the bearing material !! We are talking oil temps probably no more than

the mid to high two hundred F range where the Viton seals start to break down

and harden.......IMHO

Kelly

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