Return-Path: Received: from relay01.roc.ny.frontiernet.net ([66.133.131.34] verified) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 3067908 for flyrotary@lancaironline.net; Sun, 07 Mar 2004 15:23:25 -0500 Received: (qmail 25318 invoked from network); 7 Mar 2004 20:22:55 -0000 Received: from unknown (HELO frontiernet.net) ([170.215.96.68]) (envelope-sender ) by relay01.roc.ny.frontiernet.net (FrontierMTA 2.3.6) with SMTP for ; 7 Mar 2004 20:22:55 -0000 Message-ID: <404B84B4.165D9891@frontiernet.net> Date: Sun, 07 Mar 2004 14:23:16 -0600 From: Jim Sower X-Mailer: Mozilla 4.77 [en] (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Cooling System Dynamics References: Content-Type: multipart/alternative; boundary="------------708B93CC8060AA54D9199DE0" --------------708B93CC8060AA54D9199DE0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit I would guess there's a temperature threshold somewhat below operating temp at which the pressure is pretty close to operating pressure. If that is so: Have the temperature, as it rises above that threshold enable the pressure alarm which would activate when pressure dropped. Overpressures (like firing into the water jacket) would activate the pressure alarm regardless of temperature. Just a theory .... Jim S. lonnwood wrote: > Tracy, this has got me to thinking about an alarm system that > would be useful for the coolant pressure gauge.A simple > pressure activated warning light would not be useful because > the pressure starts out at zero andgradually builds, then > during different modes of flight when your engine cools the > pressure would go back down.Not having flown with a water > cooled system yet I don't know how much it would > fluctuate.Would it be worthwhile to have a small processor > programmed to keep track of engine temps and comparethose to > what the coolant pressure should be, then set the alarm off if > they don't add up?Lonnie > > The best advice I can give is to learn the behavior > (not just the static reading) of your coolant > pressure gauge and pay attention to any anomaly. It > tells the whole story IF you know how to interpret > it. Tracy Crook > --------------708B93CC8060AA54D9199DE0 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit I would guess there's a temperature threshold somewhat below operating temp at which the pressure is pretty close to operating pressure.  If that is so:
Have the temperature, as it rises above that threshold enable the pressure alarm which would activate when pressure dropped.
Overpressures (like firing into the water jacket) would activate the pressure alarm regardless of temperature.

Just a theory .... Jim S.

lonnwood wrote:

Tracy, this has got me to thinking about an alarm system that would be useful for the coolant pressure gauge.A simple pressure activated warning light would not be useful because the pressure starts out at zero andgradually builds, then during different modes of flight when your engine cools the pressure would go back down.Not having flown with a water cooled system yet I don't know how much it would fluctuate.Would it be worthwhile to have a small processor programmed to keep track of engine temps and comparethose to what the coolant pressure should be, then set the alarm off if they don't add up?Lonnie
The best advice I can give is to learn the behavior (not just the static reading) of your coolant pressure gauge and pay attention to any anomaly.  It tells the whole story IF you know how to interpret it. Tracy Crook
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