X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [66.219.56.248] (HELO qnsi-xch.qnsi.net) by logan.com (CommuniGate Pro SMTP 5.0.8) with ESMTP id 983294 for flyrotary@lancaironline.net; Mon, 13 Feb 2006 15:15:55 -0500 Received-SPF: none receiver=logan.com; client-ip=66.219.56.248; envelope-from=bhughes@qnsi.net Content-class: urn:content-classes:message Return-Receipt-To: "Bobby J. Hughes" MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C630DA.5F5BE6E0" Disposition-Notification-To: "Bobby J. Hughes" X-MimeOLE: Produced By Microsoft Exchange V6.5.6944.0 Subject: RE: [FlyRotary] Re: Renesis Cooling oddity Date: Mon, 13 Feb 2006 14:16:28 -0600 Message-ID: X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [FlyRotary] Re: Renesis Cooling oddity Thread-Index: AcYlRJdeXYtjnxgeQsKzmEQNLOQIwQLlUZYA From: "Bobby J. Hughes" To: "Rotary motors in aircraft" This is a multi-part message in MIME format. ------_=_NextPart_001_01C630DA.5F5BE6E0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Tracy, =20 Did the lower coolant temps have any effect on your Oil temps? I had my stock Mazda cooler tested last week to 200 psi. Still debating on going with it or a larger Fluidyne. =20 Bobby ________________________________ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Tracy Crook Sent: Sunday, January 29, 2006 8:24 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Renesis Cooling oddity As Ed mentioned in a recent post, He gave me his spare radiator cap when mine was found to be defective. It had been bad since day one when I installed it on the Renesis installation. I had noticed that the coolant pressure was low (almost zero) after the engine cooled down after initial climb out but had written it off as normal for the new system since it was cooling adequately. =20 I've been flying with good pressure after replacing the cap and noticed that the cooling system performance was generally better. What really interested me was the change in temp differential between the water temp at the combustion chamber side and the intake/exhaust port side (I measure it in both locations). Previously, there was an 8 - 10 degree rise in coolant temp as it went through the port side and I had assumed this was due to the increased exhaust port heat transfer to the coolant on the Renesis. This really bugged me since it represents a LOT of BTU into the coolant. Now that the coolant pressure is normal (~10 psi at cruise) the port side temp increase is down to 1 - 3 degrees. The question is, why? =20 So far, the leading theory is water pump cavitation. The low coolant pressure allowed the pump to cavitate which reduces coolant flow rate which in turn caused the temp rise to be higher. As a side note, the Renesis uses the same pump design as the 3rd gen, a cheap stamped sheet metal impeller instead of the nicely scrolled cast impeller of the 2nd gen. I think the stamped impeller is more likely to cavitate. =20 =20 Anyway, this almost eliminates what I considered to be the only down side to the Renesis vs the earlier 13B. =20 Tracy ------_=_NextPart_001_01C630DA.5F5BE6E0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable
Tracy,
 
Did the = lower coolant=20 temps have any effect on your Oil temps? I had my stock Mazda cooler = tested last=20 week to 200 psi. Still debating on going with it or a larger=20 Fluidyne.
 
Bobby

From: Rotary motors in aircraft=20 [mailto:flyrotary@lancaironline.net] On Behalf Of Tracy=20 Crook
Sent: Sunday, January 29, 2006 8:24 PM
To: = Rotary=20 motors in aircraft
Subject: [FlyRotary] Re: Renesis Cooling=20 oddity

As Ed mentioned in a recent post,  He gave = me his=20 spare radiator cap when mine was found to be defective.  It had=20 been bad since day one when I installed it on the Renesis=20 installation.  I had noticed that the coolant pressure was low = (almost=20 zero) after the engine cooled down after initial climb out but had = written it=20 off as normal for the new system since it was cooling=20 adequately.
 
I've been flying with good pressure after = replacing the=20 cap and  noticed that the cooling system performance was generally=20 better.  What really interested me was the change in temp = differential=20 between the water temp at the combustion chamber side and the = intake/exhaust=20 port side (I measure it in both locations).  Previously, there = was an 8 - 10 degree rise in coolant temp as it went through the = port side=20 and I had assumed this was due to the increased exhaust port heat = transfer to=20 the coolant on the Renesis.  This really bugged me since it = represents a=20 LOT of BTU into the coolant.  Now that the coolant pressure is = normal (~10=20 psi at cruise) the port side temp increase is down to 1 - 3 = degrees.  The=20 question is, why?
 
So far, the leading theory is water pump = cavitation. =20 The low coolant pressure allowed the pump to cavitate which reduces = coolant flow=20 rate which in turn caused the temp rise to be higher.  As a = side note,=20 the Renesis uses the same pump design as the 3rd gen, a cheap stamped = sheet=20 metal impeller instead of the nicely scrolled cast impeller of the 2nd=20 gen.  I think the stamped impeller is more likely to = cavitate. =20
 
Anyway, this almost eliminates what I considered = to be the=20 only down side to the Renesis vs the earlier 13B.
 
Tracy
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