-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of Steve Brooks
Sent: Sunday, September 19, 2004 12:55 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Still high temperature

I would appreciate input to a problem that I have.  I just overhauled
the
engine, and reworked the cooling system.  I'm now using the A/C
evaporator
cores for radiators.  The problem I'm having is, that when I take it up,
I'm
seeing coolant and oil temperature of about 210 degrees.  That is
climbing
to pattern, leveling off, and throttling back to low power.  The oil
stays
pretty much where it is, and the coolant come down just a couple of
degrees.

When throttle back to land, the coolant and oil both come down to about
180
at touchdown.  I taxi back to the hanger and shut down with oil and
coolant
about 190-195, but after shut down, I get all sorts of gurgling noises
from
the header tank, which is fed by the tap on the side of the thermostat
housing.  The gurgling noises go on for 5-6 minutes, which would seem
like
the engine is overheated, but while hot, it doesn't seem overly hot. The
other end of the header tank feeds coolant to the turbo, so maybe the
hot
water is coming from it ? Maybe my header tank should be fed differently
?
Also at this time, after a short flight, there is only a couple of cups
of
additional coolant in the overflow tank.

I assume that the higher than desired coolant temperature, and the
gurgling
noise are related.  I pulled the water pump off today to double check
it,
and all seems OK.  The pump only has about 10 hours on it.  When I run
it on
the ground, and feel the radiators after shutdown, they are uniformly
hot.
I put a furnace blower pointed at the scoop, and I'm getting very even
airflow through the radiators.  The oil cooler, on the other hand, has
about
75% of the air going through the middle of the cooler, so I'm going to
have
to add some deflectors in the plenum to push more air to the outside.
That
seems to be a less significant issue at the present.

Any thoughts ?

Steve Brooks
Cozy MKIV
Turbo rotary

My FD (1994 tt 13Brew) engine typically runs 210-225F all summer on
highway drives. I have two water temp sensors. Today with ac on, 70 mph,
95F outside, 500'msl, 212F sustained (ac turns on electric fans as
well)-nowhere near your power output in flight! Getting those temps down
probably means a bigger radiator, better airflow, and bigger fans.
Gurgling in the FD means you have air in the system, burp it well (bleed
air at the highest point in the system off somewhere while filling it,
this is a critical FD step).
Marc Wiese