Water Heater Connection Change increased SS top speed 20%
Moving the water heater from the heat exchanger line to the thermostat by-pass increased my steady state (over two hours) top speed by close to 20%. see
For more details on how to change it see
My engine is a 1980'' 32HP Universal 5432 that is very similar to the Westerbeke M40 of the 1980''s.