Cooling System; Description Of The System - Rotax 914 series Installation Manual

12) Cooling system

12.1) Description of the system

See Fig. 14.
The cooling system of the ROTAX 914 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 expansion tank
and overflow bottle.
The coolant flow is forced by a water pump, driven from the camshaft, from the
radiator to the cylinder heads. From the top of the cylinder heads the coolant passes
on to the expansion tank (1). Since the standard location of the radiator (2) is below
engine level, the expansion tank located on top of the engine allows for coolant
expansion.
The expansion tank is closed by a pressure cap (3) (with pressure relief valve and
return valve). At temperature rise and expansion of the coolant the pressure relief
valve opens and the coolant will flow via a hose at atmospheric pressure to the
transparent overflow bottle (4). When cooling down, the coolant will be sucked back
into the cooling circuit. See therefore SB-914-025 "Modifications of the overflow
bottle", latest issue.
2
The shape, size and location of one or more radiators depend mainly on the space
available.
BRP-Rotax offers optional radiators, these radiators when properly installed in
winged aircrafts has proven its worth in regard to the operating limits. The flow
resistance of the cooling liquid in the radiator is adjusted well to the cooling system.
Make sure that the diameter of the conduction is sufficient.
Effectivity: 914 Series
Edition 2 / Rev. 0
BRP-Rotax
INSTALLATION MANUAL
3
1
4
Fig. 14
09152
page 43
July 01/2008