X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao04.cox.net ([68.230.241.35] verified) by logan.com (CommuniGate Pro SMTP 4.3.5) with ESMTP id 1022373 for flyrotary@lancaironline.net; Sun, 26 Jun 2005 17:00:53 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.35; envelope-from=ALVentures@cox.net Received: from BigAl ([68.7.14.39]) by fed1rmmtao04.cox.net (InterMail vM.6.01.04.00 201-2131-118-20041027) with ESMTP id <20050626210007.XJDU23392.fed1rmmtao04.cox.net@BigAl> for ; Sun, 26 Jun 2005 17:00:07 -0400 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Coolant Leak Date: Sun, 26 Jun 2005 14:00:16 -0700 Message-ID: <000001c57a92$0da75090$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C57A57.61487890" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C57A57.61487890 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable =20 I agree, Al. I don't see how that much heating of the coolant could = happen in a second or two. I personally think it has to do with lack of any = air in the system as it does not do that when there is air present. Could the = fact that I used stainless steel braided lines for the coolant system = minimize expansion? In any case, I have flow with that condition for several = hundred hours with no apparent ill effect, so it does not appear to be anything detrimental to the operation of the engine. =20 Ed =20 The important thing is that; whatever the cause, the pressure transient = is apparently a non-issue. Certainly lines covered with braided SS = aren't going to expand much, but they still have flexible walls in there that = do distort bit with pressure, as will the thin-walled tank on a radiator. Clearly there is a hydraulic pressure being transmitted through the = cooling system. My guess is that the cause is likely the immediate expansion of = the inside walls of the rotor housing (temperature and pressure) while everything else is cool, followed closely thereafter by initial heating = of the coolant. Heat transfer through the rotor housing does not happen instantaneously. It's a guess, but hey; other than for mental = gymnastics, who cares? =20 Al ------=_NextPart_000_0001_01C57A57.61487890 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

I agree, Al. I don't = see how that much heating of the coolant could happen in a second or two. = I personally think it has to do with lack of any air in the system as it = does not do that when there is air present. Could the fact that I used = stainless steel braided lines for the coolant system minimize expansion? In = any case, I have flow with that condition for several hundred hours with no apparent ill effect, so it does not appear to be anything detrimental to = the operation of the engine.

Ed

The important thing is that; = whatever the cause, the pressure transient is apparently a non-issue. = Certainly lines covered with braided SS aren’t going to expand much, but = they still have flexible walls in there that do distort bit with pressure, as will = the thin-walled tank on a radiator. Clearly there is a hydraulic = pressure being transmitted through the cooling system. My guess is that the = cause is likely the immediate expansion of the inside walls of the rotor = housing (temperature and pressure) while everything else is cool, followed closely thereafter = by initial heating of the coolant. Heat transfer through the rotor housing = does not happen instantaneously. It’s a guess, but hey; other than for = mental gymnastics, who cares?

Al

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