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Mark,
Interesting data, to help me understand it better
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1. Oil flow from engine to oil/water cooler to
oil/air cooler to engine? where is the temperature measured?
2. Where is water temp measured?
3. What was water temp under similar conditions
prior to the change?
Bill Schertz
KIS Cruiser #4045
----- Original Message -----
Sent: Tuesday, October 23, 2007 8:00
AM
Subject: [FlyRotary] Cooling Update -
Lancair ES/20B
OK, I was going to wait to discuss this at the fly-in, but I
was chastized for keeping this to myself, so here goes.
My 3-rotor
Lancair ES has had excessive oil temps of 225 - 235*F (in climb) since first
flight. Opening the cowl exit area helped enough to get me in the air
for more than a lap around the pattern, but I was climb-limited to about
500fpm. I was anticipating better performance once the Texas summer heat
subsided, but that just didn't happen this year (temps in the high 80's just
last weekend). So, I decided to try an oil/water heat exchanger. I
found a NASCAR Fluidyne unit on ebay and managed to "win" the bid. It
required that I do major surgery to the cooling system, including relocating
some items on the firewall to make room for the new heat exchanger. I
finished it up Sunday afternoon and did a couple of ground runs and things
looked promising (it didn't leak). So, I decided to go for a short test
flight.
I set the M/T constant speed prop to 2300 rpm,
which will give me takeoff rpm in the mid to upper 6K range. OAT was
about 88*F. I accelerated and where I would normally have to throttle
back to keep temps under 230*F, the temps were in the 180* range. So, I
kept the power on, climbing like I have never climbed before (1400 fpm).
This is a 4-place, 2100# empty airplane. I kept it WOT until I reached
2000 msl (1500agl) and then noticed that I forgot to retract the 10* flaps
used for takeoff. So, I cruised around at 2500 - 3000 msl and water temp was
170 - 177*F, oil temps were 160 - 165*F. Before this mod, my oil temps
would normally be approx. 185 - 190*F in cruise. Needless to say, I was
very happy.
The difference in my oil/water arrangement is that I
tapped the water pump with a 1/2" line just before it enters the front side
housing and I use this "cool" water to supply the water to the oil/water
exchanger. I return the heated water to the engine discharge leading to
the radiator. I felt this would still provide sufficient coolant flow
through the engine as some guys are running the smaller 13B pump on their
3-rotor engines without a problem. The 20B water pump impeller is 1/4"
larger diameter. From my initial flight, it seems that there is
plenty of coolant flow to keep the engine cool.
It is really too early
to tell for certain, but things look very promising. I will try and take
some pictures to bring with me to the Rotary Fly-In.
Finally, to
give credit where credit is due, I am told that Leon (from down under) has
been using this design for years with great success. I thank Leon for
sharing his racer tricks with the group.
Mark S.
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