S201 AFM
7 - AIRPLANE AND SYSTEMS
DESCRIPTION
7.9 - POWERPLANT
27/06/2019
SONAIR-S2-D-MAN-006
Page : 7-62
Rev. : A
7.9.2
COOLING SYSTEM
The Rotax 914 features dual cooling means:
•
Cylinders are air cooled.
•
Cylinder heads are liquid cooled via a closed circuit system with an
expansion tank. A camshaft driven coolant pump circulates coolant
from a radiator through the cylinder heads, then through an expansion
bottle and back to the radiator.
The expansion tank is closed by a pressure cap. At temperature rise of the
coolant an excess pressure valve in the expansion tank opens and coolant flows
(via a hose) at atmospheric pressure to an overflow bottle mounted on the
firewall. When cooling down the coolant in the overflow bottle is sucked back
into the cooling circuit.
Refer to latest revision of Rotax operator / maintenance manuals and latest
revision of Rotax service instruction SI-914-019 with regard to selection of
operating fluids.
COOLANT
Grade / type
1:1 Ethylene glycol based
coolant and distilled
water mixture.
Type : YACCO LR-35
Organic
Do not use concentrated
waterfree propylene glycol
based coolant.
See section 2.5.