Return-Path: Received: from fed1rmmtao02.cox.net ([68.230.241.37] verified) by logan.com (CommuniGate Pro SMTP 4.2b1) with ESMTP id 3152035 for flyrotary@lancaironline.net; Thu, 08 Apr 2004 01:56:02 -0400 Received: from BigAl ([68.107.116.221]) by fed1rmmtao02.cox.net (InterMail vM.6.01.03.01 201-2131-111-101-20040311) with ESMTP id <20040408055601.JXYX8783.fed1rmmtao02.cox.net@BigAl> for ; Thu, 8 Apr 2004 01:56:01 -0400 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Cooling Problem Date: Wed, 7 Apr 2004 22:56:17 -0700 Message-ID: <003101c41d2e$355f84d0$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0032_01C41CF3.8900ACD0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 Importance: Normal In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_0032_01C41CF3.8900ACD0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Do you think that there is any chance that the lack of back pressure is causing the coolant to not flow well? David Leonard No. Less back pressure equals flow. It's the law for centrifugal pumps. The only benefit to putting flow restriction at the thermostat is to increase the coolant pressure in the engine. If you are running at speeds greater than say, 6500 RPM it may (depending on other things) reduce the risk of pump cavitation. It would seem there are only about two possibilities; air trapped in the pump housing, or incorrect flow path resulting in flow recirculating in the engine. But then, you sems to have worked those. Al ------=_NextPart_000_0032_01C41CF3.8900ACD0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message

  Do you = think that there is any chance that the lack of back pressure is causing the = coolant to not flow well?

 

David = Leonard

 

No.  Less back pressure = equals flow.  It’s the law for centrifugal pumps.  The only = benefit to putting flow restriction at the thermostat is to increase the coolant = pressure in the engine.  If you are running at speeds greater than say, 6500 = RPM it may (depending on other things) reduce the risk of pump = cavitation.

 

It would seem there are only = about two possibilities; air trapped in the pump housing, or incorrect flow path resulting in flow recirculating in the engine.  But then, you sems = to have worked those.

 

Al

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