Dale wrote:

I believe there is a requirment that the engine must be able to operate
at rated power within allowable temps with only 50% of the oil sump
capacity. If so that might explain why sumps are seemingly "oversized".

According to the manual that came with my O-320, it will run at rated power
with as little as 2 quarts of oil. Since the sump holds 8 quarts, it would
seem that there isn't a relationship there.

George Patterson
You can dress a hog in a tuxedo, but he still wants to roll in the mud.