Cotten! Assuming that the check ball is nowhere near a "tight" fit in the passage (so that it otherwise becomes the flow restriction), and that the hole was the same size, and that ball lift off the seat was the same, the smaller ball would pass more oil!
On the other hand, you are also right that a larger orifice [and all other things being equal](and therefore the perimeter of orifice is longer) will pass more oil.
The differences are too small here to generalize too far, I'm afraid.
[This message has been edited by Guy Winton III (edited 01 February 2001).]