That compression ratio is exactly my concern for him.Peninsular marine engines were 18:1 for a reason, have been for a long time, not saying that is your current trouble. Where and when did you get the ip ? Is it used, if so how old is it?
I am old school more comfortable with high compression in these but man- driving that supercharger at that boost with the compression up there and it has to be sustained for so many hours....
there is a reason people pay big bucks to have the engine tuned on the dyno— because itnis cheaper in the long run.
Guys piece part together engines like this in pickups and cars no biggie because 4 free tows a year comes with most everyone’s car insurance. Idk about free boat towing, let alone what happens when the crankshaft goes out the oilpan.