Rotax 912 Series Installation Manual page 53

Once the calculation is made and the indicating instrument re-labelled it is
acceptable to use the cylinder head temperature as the primary cockpit display
instead of installing a sensor in the coolant flow.
The measurement is based on the maximum coolant temperature and cylinder
head temperature according to the current requirement.
■ CAUTION:
Refer to the flight test example that follows.
c) Cooling capacity of the installation too low.
Flight test example:
Calculated values (maximum values found for coolant temperature and cylinder
head temperature. Refer to the current specification of the FAA and/or EASA):
Coolant temperature.....................102 °C (216 °F)
Cylinder head temperature...........110 °C (230 °F)
The cylinder head temperature is 8 °C (46 °F) higher than the coolant
temperature.
Thus:
Coolant temperature limit...............................................120 °C (248 °F)
Difference cylinder head and coolant temperature..........+
The highest cylinder head temperature permitted is 128 °C (262 °F), so that the
max. coolant temperature is kept.
With this special application, safe operation of the engine that prevents boiling
of the coolant is possible up to a cylinder head temperature of 128 °C (262 °F).
■ CAUTION:
■ CAUTION:
Effectivity: 912 Series
Edition 1 / Rev. 0
BRP-Rotax
INSTALLATION MANUAL
In no case a cylinder head temperature higher than the limit of
150 °C (300 °F) (for ROTAX 912 UL/A/F) and 135 °C (275 °F)
(for ROTAX 912 ULS/S) can be defined because detonation
could not be sufficiently prevented.
This cylinder head temperature with the limit found for this type
must be displayed constantly in the cockpit.
The indicating instrument and the manuals must be changed
to cylinder head temperature max. 128 °C (262 °F).
The design of the radiator installation must be changed
(example: cowl modifications), if the operating temperature
exceeds the specified limits.
8 °C ( 46 °F)
= 128 °C (262 °F)
page 53
May 01/2007