rob
It was somewhat of a loaded question. You want to use a lower temp thermostat not because of the sea temperature, but because it contains certain salts. But, a diesel runs happier at higher temps, so if on a freshwater lake or river you use a higher temp thermostat.
Certain salts in seawater become less soluble as the water temp rises (at least in the range of temps in which our engines operate.) Strange, because we know that table salt (sodium chloride) dissolves easier in hot water than in cold. But, for instance, so does sodium sulfate -- but above 50 C (122 F) its solubility decreases. So to lessen the opportunity for salts to precipitate out, a lower thermostat is installed to keep the engine coolant a little cooler, which keeps the seawater cooler. This is a particular problem in seawater-cooled engines, like the original Atomic 4 because salt deposits would build up and block internal engine cooling passageways. So that had a 140 F thermostat.
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Topic: Thermostat source (Read 2655 times)