Received-SPF: pass
 receiver=logan.com; client-ip=24.25.9.103; envelope-from=echristley@nc.rr.com
Message-ID: <423F7E4A.9010706@nc.rr.com>
Date: Mon, 21 Mar 2005 21:09:14 -0500
From: Ernest Christley <echristley@nc.rr.com>
User-Agent: Mozilla Thunderbird 0.9 (X11/20041127)
MIME-Version: 1.0
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: EWP: How much is enough
References: <list-813741@logan.com>
In-Reply-To: <list-813741@logan.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit

This seems to be the big question.  How much is enough? 

The premise is that lowering the flow allows the water to get BOTH 
hotter and colder.  It stays in the engine longer (getting hotter), then 
stays in the radiator longer (getting colder).    The limiting factor is 
the MAX temperature.  It can fluctuate all it wants under the max, but 
we've got to keep those hotspots below 210F.

But I think an engine with an EWPs is in a unique position to give us 
the information we need, since it's flowrate can be electrically 
controlled.  I propose the following experiment (which is easy for me 
seeing as I don't have a running engine).

-mount thermocouples to measure the water temp going in and coming out 
of the engine.
-mount a flowmeter inline
-connect a variable voltage source across the EWP
-run the engine up to normal operating temp
-using a rheostats or some type of regulator, start the EWP at 14V and 
measure the deltaT across the engine after it stabilizes.
-successively drop the voltage in 1/2 or 1/4 V increments, recording the 
flow, letting the temps stabilize and then recording at each step.

Graphing the results should tell us what flow will give what deltaT.

-- 
This is by far the hardest lesson about freedom. It goes against
instinct, and morality, to just sit back and watch people make
mistakes. We want to help them, which means control them and their
decisions, but in doing so we actually hurt them (and ourselves)."