Received-SPF: none
 receiver=logan.com; client-ip=204.127.192.84; envelope-from=rlwhite@comcast.net
Date: Mon, 24 Jul 2006 18:38:13 -0600
From: Bob White <rlwhite@comcast.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: More cooling Tests
Message-Id: <20060724183813.ba9ab204.rlwhite@comcast.net>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit

I finished putting a layer of insulation around the exhaust system.  I
placed thermocouples in a few key locations.  One inside the
insulation, one outside, and one on the fuel rail.  OAT was 80-85F.

I ran the engine at 2200 rpm until the temps stabilized at 197 oil and
water.  I increased rpm's to 3100 and temps went up to 200 oil and 207
water. They were still increasing very slowly.  I can taxi at 3100 rpm
or less and getting a little movement should help cooling.  Also, when
I reduced power back to 2200 rpm, the temps started decreasing.  So on a
not too hot day I think the cooling will be OK for taxiing.

The insulation is a layer of reflective insulation I bough at the speed
shop that is good to 1000F.  It has a metalized layer on each side and
some kind of fibrous layer on the inside.  (The stuff itches like
fiberglass when you get it on you.)  At the end of the test, the
thermocouple on the inside layer was reading 235F and the one in the
same place on the outside of the insulation was 167F.

I still don't have the fuel return to the tank.  It's going directly
back to the fuel pump input.  So the fuel rail temps were getting
pretty high.  The fuel rail was 145F and the engine was starting to run
a little rough, presumably due to incipient vapor lock.

Next step is to open the tank and install the fuel return line.  I ran
the line from the firewall to the wing root this afternoon, so the easy
part is done.

Bob W.

-- 
http://www.bob-white.com
N93BD - Rotary Powered BD-4 (first engine start 1/7/06)
Custom Cables for your rotary installation -
http://www.roblinphoto.com/shop/