Like Mumbles said, yours is a plain sleeve type bearing motor, Clearances weren’t very tight, since machining techniques were not as close as modern days. Those clearances is why your motor needs QUANTITY, not quality of oil. The oil film is what keeps bad things from happening between the bearings and crank, rods, pins, etc. As many would say, oil is cheaper than parts.
If you have too many, AND not enough, you're a collector.