I’m new to air boating just chopped my rigging down low into the boat and replaced wood prop with whirlwind two blade carbon max. My motor as I was told by one of you awesome people on this forum is that I have a 0-300 D 6cyl continental aircraft engine. It has a small radiator that cools the oil? Any way I want to change oil and plugs and notice there is no visible oil filter? What am I missing? Any info would be greatly appreciated thanks. PaPa. D