ORIGINAL: More HP
The pressure goes through the rear bearing. Pull off the pushrod tubes and you'll see how crankcase pressure is allowed to vent alongside the cam follower and up the pushrod tube. Theoretically?
I can see the small canal in holes for valvelifter, it allow oil to pass from crankcase to the valves at the cylinder head therefore it give enough lube for the valvelifter and the valves since the engine are running hi revolution. Smart solution!!!
Jens Eirik