As the lobe dips into the trough, it picks up oil.  Then, as the lobe continues rotation most of that oil is thrown aft onto the intake valves (paddlewheel effect).  Then, the lobe encounters the cam follower.  The pad on the cam follower wipes any remaining oil off the lobe.  By the time the lobe clears the cam follower, there simply isn’t any more oil left on the lobe.  So, IMO, the exhaust valves get their lubrication from the holes in the cam lobes.  That’s a very important point since the left-hand main bearing and balancer bearing are lubricated by drain oil from (you guessed it) the exhaust valve spring pocket.

This picture should drive the idea home.  See how the cam follower wipes off the lobe and squeezes the oil out the back side.  The only way for oil to go forward into the exhaust valve pocket is via the holes in the lobes.  Since it’s pressurized oil, it will spray out of the holes.

This is the all-important drain hole.  It supplies the oil to the left-hand bearings.

At the base of the cylinder, the drain enters a keyhole shaped cavity.

Fill the exhaust spring pocket with oil and you can watch the oil cascade over the left-hand bearings.

The right-hand side has a similar system.  Instead of a drain hole, the oil simply spills over the edge of the intake valve spring pocket (like Niagra Falls).

The right-hand balancer bearing has this contraption that gathers up stray oil and directs it to the edge of the bearing.  Reminds me of a coal chute.

The transmission shafts and clutch are fed oil through this .071” orifice.  The orifice restricts the flow, so the pressure inside the transmission shafts is somewhat less than the pressure in the rest of the system.