From: Steve Brooks <cozy4pilot@gmail.com>
Subject: [FlyRotary] Back in the air
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Date: Sunday, August 3, 2008, 9:33 AM
I’ve had my plane torn apart for about 3 ½ months
rebuilding the cooling
system, in between vacation, wife’s projects, and
problems fitting in the
radiator.  I installed a custom made radiator, replacing
two evaporator
cores that I was using.  The evaporator cores provided only
marginal cooling
for the turbo 13B, in a pusher aircraft

In order to install the new radiator, I also had to
relocate almost all of
the fuel system components, and I replaced the aluminum
lines connecting the
fuel pumps to filters to regulator with SS braided AN
hose/fittings.
Due to the extensive changes, I had at least an hour, maybe
hour and a half
of ground testing, including four high speed taxi’s up to
rotate speed.

The new cooling system also has a cooling fan which I was
able to integrate
into the plenum holding the radiator.  At 95 F degrees OAT,
and turning the
fan on at about 190 F degrees coolant temperature, The fan
maintained 180 F
for 20 minutes of ground operation, including some high
power testing.

This morning OAT was about 78 F, which is very good for
North Carolina in
August,  I wanted something less than 95 F for the first
test of the new
cooling system.  I did not use the cooling fan for taxi or
takeoff, as I
wanted to see what the cooling was without the fan.  I took
of and climbed
up to about 1200’ AGL.  The coolant was up to about 205,
and oil at 185.  I
leveled off and reduced the throttle to normal cruise
power.  I watched the
coolant temperature for a little while (maybe 15-20
seconds), and it seemed
to stay at the 205 F reading.  I wish now that I’d been a
little more
patient, but I kicked on the cooling fan, and the
temperature came down
pretty quickly to slightly above 180 F.  I turned the fan
off again and the
temperature stayed right there.  I did power up and climb
another 300 feet
or so, but really didn’t push it too hard on the first
flight.  The
temperature didn’t really move too much during the brief
climb.  All other
systems ran perfectly and it was a very nice flight.  I did
stay within
gliding distance of the runway the whole flight, but based
on zero squawks
on this flight, the next one will be longer.

While I would like to have seen a little better
performance, I was happy
with the improved cooling over the old system.  Climbing to
pattern altitude
old the old system at today’s temperature would have been
215 – 220F.  On
the next flight, I’ll take off using the cooling fan, and
see what kind of
numbers I get with it.  I hope to see something more in the
185-190 range,
but I’ll have to see what the real number are.


Steve Brooks
Cozy MKIV N75CZ
Turbo rotary