Scania is a great choice if your in need of a bigger liter engine. The 13 and 16 liter engines have served our local commercial fisherman and recreational boats well. Great torque and fuel consumption along with above standard technical and parts support.
I like Cummins for there 6.7 liter and 8.3 liter engines. Both easy to work on and great parts availability. Both engine have great power to weight ratios at they’re recreational ratings, and known to be commercial work horses as well.
Yanmar is my go to for sailboat repowers, but also like the other engines in there line. The 8LV is an incredible motor. It is quiet and has lots of torque. You can’t beat the technical and parts support either.