Engine cooling system
Rotax 503 cooling system
The Rotax 503 engine (Sinus ultralight motorglider Model 503) is aircooled by use of own fan. Cold
air enters through the opening on the top engine cover and is forced to spread over the engine ns.
The air then blown out of the engine compartment just below the rewall.
Rotax 582 cooling system
The Rotax 582 engine (Sinus ultralight motorglider Model 582) is watercooled. The cooling uid
circulates through the hoses via twin cooling circuit. For that an integrated pump is used. When the
engine is still cold (cold start), the thermostat allows for the uid to circulate around the cylinders
only. Later, when the engine warms-up the thermostat switches cooling mode and the cooling uid
passes through the radiator as well.
The whole system is pressurised with a pressure valve located on top of the radiator. The overow
tank uid level must always be inside designated limits!
The manufacturer recommends use of cooling uids used in car industry diluted in such a manner
that it withstands temperatures as low as - 20° C.
Schematic of engine cooling system - model 582
Aircraft and systems on board