912 crankcase pressure

[Pat Oden]

When the 912 engine is running is there positive pressure in the sump top push the oil into the oil resivour(sp)?

[Dave S]

Pat,

That is affirmative. Blow by pressurizes the crankcase, sort of like that atificially provided by rotating the prop to burp the engine before checking the oil.

Normal operations the breather tube attached to the top of the oil tank just below the filler pipe vents blow-by overboard. The oil filler cap has a spring/disk that serves as a calibrated pressure relief to limit crankcase/oil tank pressure.

Sincererly,

Dave S
KF7 Trigear - flying
912ULS Warp

[Av8r3400]

Yes.

There is no crank case breather for a 912. The oils sump acts as the breather.

[Pat Oden]

Thanks guys, this is good info, I appreciate it.