I can't specifically answer except to say I have a 31, which is about 1,000 pounds less displacement, with a Universal M-18 rated at 14 horsepower. That has always been enough but I think it is on the conservative side. Based on that I would think 18 horsepower in the 32 would probably be enough but on the lower side of that. Hopefully an owner of a 32 with the Volvo will chime in with an opinion.