David C, nice pix of the motors. a bit bigger than the ones on 50 foot fishing boats where I worked 40 years ago. Most of these were 2 cylinder 2 stroke diesels, red lined at 400RPM for 110 HP, flywheel was 10 feet diameter and 2 feet thick!! direct drive to screw with variable pitch prop, single plate dry clutch> Still lots of torque at 60 RPM for a winch and hydraulics towing a trawl in 400 feet of water at 6MPH

Hundested motor from denmark