Never having the chance to work on the 216 I know very little about them, but I would think if the dippers actually dipped into the oil in the pan then it would aerate the oil to the point it couldn't pump.
My impression was that the nozzles squirted the oil into the dipper as it came around close enough to catch the oil coming out of the dipper regardless of engine speed. I guess that may depend on oil pressure.
But I haven't really studied the 216's much.
