BMW S58, Руководство пользователя

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S58�Engine
7.�Oil�Supply
53
7.7.�Centrally�controllable�piston�cooling�via�oil�spray�nozzles
In�addition�to�the�bearing�positions,�the�oil�pump�also�supplies�the�oil�spray�nozzles�with�the�required
volumetric�flow,�whereby�the�consumption�of�the�oil�spray�nozzles�significantly�influences�the�power�of
the�oil�pump.
For�that�reason,�the�S58�engine�is�the�first�petrol�engine�to�feature�centrally�controllable�piston�cooling.
Deactivating�the�piston�cooling�reduces�the�oil�pump�power.�In�turn,�this�reduces�the�power�loss�of�the
engine�and�saves�fuel�in�the�partial�load�range�with�the�same�vehicle�performance.
The�centrally�controllable�piston�cooling�has�the�following�special�features:
• Additional�oil�ducts�in�the�cylinder�crankcase
• Oil�spray�nozzles�without�defined�opening�pressure
• Piston�cooling�control�valve
• Piston�cooling�relay�valve.
The�central�valve�controls�the�oil�spray�nozzles�on�the�exhaust�side�of�the�crankcase.�This�enables
requirement-based�piston�cooling�over�the�entire�characteristic�map�range�of�the�engine.
The�following�system�overview�provides�an�initial�outline�of�the�structure�of�the�piston�cooling�in�the
S58�engine.
S58�engine,�piston�cooling
Index Explanation
A Piston�cooling�active�(piston�cooling�control�valve�de-energized)
B Piston�cooling�not�active�(piston�cooling�control�valve�energized)
C Oil�pressure
D Depressurized
1 Oil�pump
2 Oil�spray�nozzle
3 Oil�duct�to�the�oil�spray�nozzles