Message-ID: <40480F4F.1020606@netzero.net>
Date: Fri, 05 Mar 2004 00:25:35 -0500
From: Finn Lassen <finnlassen@netzero.net>
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Ideal Cooling System Plumbing (was Re:  [FlyRotary]
 Re: overflow connections
References: <list-3063490@logan.com>
In-Reply-To: <list-3063490@logan.com>
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David Carter wrote:

>3.  However, with ref to my last input, "coolant level", as sensed inside a
>"pressurized" coolant expansion tank - IF mounted with coolant level up near
>top of engine , will be the ABSOLUTE first AND BEST indicator of a leak:
>Coolant leaks out - anywhere, that coolant is replaced by coolant in
>"expansion/reservoir/pump header" tank until tank empties/turns on "Low"
>light.  Up to this point, the engine is FULL of liquid - no air, no nucleate
>boilng, no temp jiggles.  Then subsequent leakage will be out of engine, as
>"expansion/reservoir" tank is now empty - THEN, the PRESSURE jiggles will
>start.
>
>David
>
However, there is one failure mode (with which I'm intimately familiar) 
where sensing the coolant level in the overflow bottle (and possibly in 
pressurized expansion/header tank) will not help: Blowby from 
compression and/or combustion gasses forcing air into the coolant system 
(and the coolant out).  Actually a nice big header tank might be able to 
handle or hide it and then a increasing pressure trend would be the clue 
that it's getting worse and worse.

Finn