"Rich Hampel" wrote

A fresh water cooled (with heat exchanger) engine should have a 180
degree thermostat. You will get better combustion efficiency, etc.

No heat exchanger on this engine.


A raw water cooled (no matter if lake or sea water) should have a 135
degree thermostat. The dissolved carbonates in raw water will begin to
precipitate and foul the engine when raw water goes over about 143
deg. F.

I do recall this from heat exchanger design - We used to limit cooling water
exit temperature to 55C which is about 131F. But this was for 24/7
operation. Sailboat engine runs for so few hours, that this could perhaps be
increased a bit.

I would like to get temperature up a bit but don't know which thermostat to
order that would fit the 2QM15 .