Pete591, I think the extra volume from a larger filter in a pressurized system would only take a fraction of a second to fill ... and, of course, this assumes that the oil has drained out of the filter, past the anti-drain-back valve.
Anyone have any GPM or GPH figures for these small engine pumps?
"A bigger element means more filtration; but it also means slower filtration."
Not sure I understand or agree. A larger filtration area is less restrictive so you would get slightly more flow if the smaller filter was any restriction (which is likely). However, the larger filter area will mean oil will hit the media at a lower velocity ... kind of like a reverse venturi effect. This means particles og a given size are more likely to get caught in the media fibers as opposed to blowing on through.
All else being equal, I don't see a downside to using a larger, longer filter assuming you have sufficient clearance. I suppose if you were to replace a filter with one that is ridiculously larger (say, 8" long as opposed to the stock 2" filter) then there might be a problem with the pump being able to fill it at start-up after a very long sit (depending on the angle at rest).