Rotax 914 series Installation Manual page 49

Once the calculation is made and the indicating instrument re-labeled 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 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: 914 Series
Edition 2 / Rev. 0
BRP-Rotax
INSTALLATION MANUAL
In no case a cylinder head temperature higher than the limit of
135 °C (275 °F) 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), such that the operating temperature will not
exceed the specified limits.
8 °C ( 46 °F)
= 128 °C (262 °F)
July 01/2008
page 49