X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from an-out-0708.google.com ([209.85.132.251] verified) by logan.com (CommuniGate Pro SMTP 5.1.9) with ESMTP id 2094538 for flyrotary@lancaironline.net; Sun, 10 Jun 2007 07:31:26 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.132.251; envelope-from=msteitle@gmail.com Received: by an-out-0708.google.com with SMTP id b2so247494ana for ; Sun, 10 Jun 2007 04:30:48 -0700 (PDT) DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=QeUjpitdn98cwYupNmFbteAcCJ/9LfRkg8bhY1NDQWmrCGAVc44AhebUXy2pg58zR+jPcdVraZOBbRu9wu8x9eZbHihZ2b63acZE7GgBDofucO+FXVwaV9qKXgDdkIEYUmW0q9WO15Eb/3TZfZ/phvy8pUzgGIcywpHmWkwLSjk= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=FUBEr9ESU0Z6n0g0XpU4ORJgD+AT1Ps56senzUDLkB8MfLc+MZ5jfG9Cg8u4AdZauT+FncgD162ZfTqJt0E4SwVWb1iavmP2ittvITKddwZCgsApOaxe9hJ3N7Rueq9WKdkjsHRZnpf1rgR16h1K5cTSfbGb8IIYmQOARo5LSys= Received: by 10.100.214.8 with SMTP id m8mr2749033ang.1181475048280; Sun, 10 Jun 2007 04:30:48 -0700 (PDT) Received: by 10.100.38.20 with HTTP; Sun, 10 Jun 2007 04:30:48 -0700 (PDT) Message-ID: <5cf132c0706100430p379490d9y5092fee3cd403e3b@mail.gmail.com> Date: Sun, 10 Jun 2007 06:30:48 -0500 From: "Mark Steitle" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: Oil temp limit In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_89022_2713110.1181475048249" References: ------=_Part_89022_2713110.1181475048249 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline Lynn, Thanks for setting my mind at ease. My concern was too high of oil pressure. The EM-2 normally flashes "99" for the oil pressure when I first start. Shortly thereafter, it will drop into the mid 90's. After its warmed up, and at less than 3000rpm, it will be in the mid 80's. Rev it a bit and it comes right back up into the mid to upper 90's. And yes, It had fresh bearings 20 hrs ago. This is a factory 20B. So, from what you're saying, if my cooler and hoses are up to it then I have nothing to worry about. Mark S. On 6/9/07, Lehanover@aol.com wrote: > > In a message dated 6/9/2007 7:54:52 P.M. Eastern Daylight Time, > msteitle@gmail.com writes: > > Lynn, > > Can you address the oil pressure limits too please. My 20B runs in the > 90's (warm). Will this hurt anything. In order to check/modify the relief > valve, I would have to remove the oil pan which means removing the engine > from the airframe. If I'm ok running in this range, I will leave it as is. > I would like to hear your take on this. > > Thanks, > Mark S. > > > For years, all engines came with the same (adjustable) pressure relief > valve in the rear iron set at 71.1 pounds. That was the published number, > how many could hit that number exactly > is unknown. The front iron relief would have been about 110 pounds to > protect the oil cooler from a fast cold start up. > > In 93 the twin turbo rear relief went up to 110 PSI, with the front relief > up to 140 pounds. > > For racing with stock or near stock clearances, 115 PSI. > > With .001" extra bearing clearance all around, 100 PSI is plenty. > > Racing Beats 900 HP three rotor turbo airplane engine uses 160 PSI, but > they are leaning on it a little bit. > > Your 90 PSI is more than enough. If you can hold 75 or 80 PSI hot that is > fine. After a long run at temperature, a slow reduction in oil pressure is a > result of oil foaming. > > Foaming makes the oil pump inefficient and insulates the oil from the > coolers and the rotor heat. If that happens you can add a flat tray between > the pan and the engine to help gas off the oil. > > Lynn E. Hanover > > > > ------------------------------ > See what's free at AOL.com . > > ------=_Part_89022_2713110.1181475048249 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline
Lynn,
 
Thanks for setting my mind at ease.  My concern was too high of oil pressure.  The EM-2 normally flashes "99" for the oil pressure when I first start.  Shortly thereafter, it will drop into the mid 90's.  After its warmed up, and at less than 3000rpm, it will be in the mid 80's.  Rev it a bit and it comes right back up into the mid to upper 90's.  And yes, It had fresh bearings 20 hrs ago.  This is a factory 20B.  So, from what you're saying, if my cooler and hoses are up to it then I have nothing to worry about. 
 
Mark S.

 
On 6/9/07, Lehanover@aol.com <Lehanover@aol.com> wrote:
In a message dated 6/9/2007 7:54:52 P.M. Eastern Daylight Time, msteitle@gmail.com writes:
Lynn,
 
Can you address the oil pressure limits too please.  My 20B runs in the 90's (warm).  Will this hurt anything.  In order to check/modify the relief valve, I would have to remove the oil pan which means removing the engine from the airframe.  If I'm ok running in this range, I will leave it as is.  I would like to hear your take on this.
 
Thanks,
Mark S.
 
For years, all engines came with the same (adjustable) pressure relief valve in the rear iron set at 71.1 pounds. That was the published number, how many could hit that number exactly
is unknown. The front iron relief would have been about 110 pounds to protect the oil cooler from a fast cold start up.
 
In 93 the twin turbo rear relief went up to 110 PSI, with the front relief up to 140 pounds.
 
For racing with stock or near stock clearances, 115 PSI.
 
With .001" extra bearing clearance all around, 100 PSI is plenty.
 
Racing Beats 900 HP three rotor turbo airplane engine uses 160 PSI, but they are leaning on it a little bit.
 
Your 90 PSI is more than enough. If you can hold 75 or 80 PSI hot that is fine. After a long run at temperature, a slow reduction in oil pressure is a result of oil foaming.
 
Foaming makes the oil pump inefficient and insulates the oil from the coolers and the rotor heat. If that happens you can add a flat tray between the pan and the engine to help gas off the oil.
 
Lynn E. Hanover



See what's free at AOL.com.

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