Ron,
While I would not have a problem with Evans coolant on a system designed to
operate with it. However, the original Europa installation was not designed
to operate with Evans.
With G-JULZ, Rotax 914 monowheel, it is quite obvious that the cooling
system is working close to its maximum capacity during a sustained climb on
a summers day.
With the original configuration (oil cooler directly behind the radiator) I
had such a problem with 50/50 during a fairly slow speed climb in the Swiss
Alps behind Dave Buzz. In the end, I had to leave the formation and fly
back down the valley at an increased speed to get the temperatures back
under control.
Once back on the ground under the advice of Andy Draper, I attacked the
lower cowling with a hacksaw to take off a lip that I had misguidedly left
on. That made a slight improvement.
When I arrived back in UK, I lowered the oil cooler to the optional
position. From that point on, G-JULZ never had a temperature problem even
in the most sustained climbs to altitude.
On the introduction of Evans fluid, the temperature problems in the climb
returned. On a summers day it was necessary to level off and accellerate at
about 3,000ft to keep the temperatures within limits.
With both Evans and 50/50, in the cruise the temperatures will drop to 50
to 60 degrees C. Which is why I am just modifying the air duct exhaust with
a temperature controlled 'cowl' flap.
Incidentally, I had considered using an oil thermostat, but gave up on the
idea when I read on this site that the oilstat mod did not work too well.
The bottom line is that if you chose to use Evans coolant on the standard
Europa configuration, don't be surprised if you experience unnecessarily
high CHT temperatures.
regards,
Mike.
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