I thought Id got all the instrumentation I needed sorted out, but Ive come
across
the following items in the Rotax Installation Manual:
"2 different types of coolant are permitted.
Type 1:
- Conventional coolant based on ethylene glycol
Conventional coolant is recommended as it is commonly available and has a
greater
thermal heat transfer capability.
. . .
Permanent monitoring of coolant temperature and cylinder head temperature is
necessary.
Type 2:
- Waterless coolant based on propylene glycol
Waterless coolant is recommended if the design of the aircraft can not maintain
the coolant temperature limit.
. . .
Permanent monitoring of cylinder head temperature is necessary.
Additional monitoring of the actual coolant temperature is possible but not
necessary
for waterless coolant.
I seem to recall that Evans (waterless) coolant was the flavour of the month
some
time back, and then it fell out of favour. I understand it's more expensive
than ethylene glycol coolants as well as causing the engine to run hotter
(because
it doesnt transfer heat so well).
However, it appears from the above Rotax manual extracts that if one wants to
use
the cheaper ethylene glycol option, its necessary to have a coolant temperature
gauge as well as the CHT monitoring. And elsewhere in the manual coolant
temp monitoring is required during the test flying period even with waterless
coolant.
So, the question is - what do folks in UK generally use in the coolant system?
And if conventional ethylene glycol, what type of coolant temperature sensor do
they have and where is it fitted?
All advice born of experience welcome.
in friendship
Rowland
| Rowland Carson ... that's Rowland with a 'w' ...
| <rowlandcarson@gmail.com> http://www.rowlandcarson.org.uk
| Skype, Twitter: rowland_carson Facebook: Rowland Carson
| pictures: http://picasaweb.google.com/rowlandcarson
|