X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from zproxy.gmail.com ([64.233.162.201] verified) by logan.com (CommuniGate Pro SMTP 4.3.5) with ESMTP id 1021621 for flyrotary@lancaironline.net; Sat, 25 Jun 2005 18:37:32 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.233.162.201; envelope-from=wdleonard@gmail.com Received: by zproxy.gmail.com with SMTP id 13so73699nzn for ; Sat, 25 Jun 2005 15:36:47 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:in-reply-to:mime-version:content-type:references; b=IJPoWrCQ5CrlQ4x6f54q4+eWWszkI46RaLk74Q6GIUPxKqqHmJIJ+q506PUEpWu8A3PiTuvm3PrlYhIKi/40tMLngBy0vzzNBFQlvvR+gxaTya7X6sv7uNKWqN1YaEsfCC5CFZtqhdWB0FtSfoa3s6/Hi7JFADrQiNxlRGN7g+M= Received: by 10.36.222.29 with SMTP id u29mr3378451nzg; Sat, 25 Jun 2005 15:36:47 -0700 (PDT) Received: by 10.36.9.4 with HTTP; Sat, 25 Jun 2005 15:36:47 -0700 (PDT) Message-ID: <1c23473f05062515366f2685bf@mail.gmail.com> Date: Sat, 25 Jun 2005 15:36:47 -0700 From: David Leonard Reply-To: David Leonard To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Coolant Leak In-Reply-To: Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_2508_6587477.1119739007572" References: ------=_Part_2508_6587477.1119739007572 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On 6/24/05, Ed Anderson wrote:=20 >=20 > Al, all I can tell you is that the pressure would go immediately (within= =20 > 2 seconds) to 21-24 psi. Then as the engine warmed up the pressure would= =20 > drop to a nominal 8 psi or so. It seem likely that the pressure sensor wa= s=20 > responding to small variations in the coolant volume. But, certainly open= to=20 > another explanation. It was not coolant/combustion chamber leaks of that= =20 > much I am certain. Tracy found the same thing, have not heard any other= =20 > similar reports until John Slade mention his coolant pressure build up. > Ed >=20 It makes sense to me Ed. Heat the coolant just a little, and it needs to= =20 expand just a little. In order for any of the coolant to flow out past the= =20 cap (even just a little coolant), it must reach the pressure rating of the= =20 cap. Once the engine is warm, there is no longer any need for the coolant to=20 leave so it does not reach the full rated pressure of the cap. --=20 Dave Leonard Turbo Rotary RV-6 N4VY http://members.aol.com/_ht_a/rotaryroster/index.html http://members.aol.com/vp4skydoc/index.html ------=_Part_2508_6587477.1119739007572 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline

On 6/24/05, = Ed Anderson <eanderson@= carolina.rr.com> wrote:
 Al, all I can tell you is that the pressure= would go immediately (within   2 seconds) to 21-24 psi.  Th= en as the engine warmed up the pressure would drop to a nominal 8 psi or so= .  It seem likely that the pressure sensor was responding to small var= iations in the coolant volume.  But, certainly open to another explana= tion.  It was not coolant/combustion chamber leaks of that much I am c= ertain.  Tracy found the same thing, have not heard any other similar&= nbsp;reports until John Slade mention his coolant pressure build up.
 
Ed
 
It makes sense to me Ed.  Heat the coolant just a little, and it = needs to expand just a little.  In order for any of the coolant to flo= w out past the cap (even just a little coolant), it must reach the pressure= rating of the cap.
 
Once the engine is warm, there is no longer any need for the coolant t= o leave so it does not reach the full rated pressure of the cap.
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