Cooling System; System Description - Rotax 912 i Series Installation Manual

1) Cooling system

1.1)

System description

See
Cooling
The engine cooling system is designed for liquid cooling of the cylinder
heads and ram air cooling of the cylinders.
The cooling system of the cylinder heads is a closed circuit with an expan-
sion tank and overflow bottle.
The coolant flow is forced by a water pump, driven from the camshaft,
Coolant
from the radiator to the individual cylinder heads. The coolant flows from
the top of the cylinder heads to the expansion tank (1). Since the standard
location of the radiator (3) is below engine level, the expansion tank
located on top of the engine allows for coolant expansion.
The expansion tank is closed with a pressure cap (2) (with pressure relief
Expansion tank
valve and return valve). As the coolant heats up and expands, the pres-
sure relief valve opens and the coolant flows via a thin hose at atmo-
spheric pressure to the transparent overflow bottle (4). As it cools down,
the coolant is sucked back into the cooling circuit.
The shape, size and position of the radiator(s) depends mainly on the
Shape, size and
position
space available in the aircraft.
NOTE:
Measuring the
coolant temp.
If a GENUINE-ROTAX radiator is being used, then an oil-water heat
Radiator
exchanger must not be present. The radiator is dimensioned to cater for
the heat of the coolant and cannot cope with the additional heat generated
by the oil system.
Effectivity: 912 i Series
Edition 1/Rev. 0
BRP-Powertrain
INSTALLATION MANUAL
Fig. 2.
The coolant temperature sensor is in cylinder head 4.
75-00-00
Page 3
January 01/2012