engine smoke/vapor

[jeb1]

My 1982 Westerbeke-44 blows out water vapor or white smoke starting when the temperature reaches about 145 degrees and levels off at about 170 degrees. These are the temps when the thermostat begins to open and is fully open.
The smoke/vapor goes no higher than about 6 inches above the water, and goes no farther than about 3-4 feet behind the boat at crusing RPM (2200).
There has been no loss of cooling water, although being on a sailboat, the engine isn''t used a lot.
Any ideas?

[fer@fer]

It sounds resonable to me the exhauts expelling together with hot water, some vapor too, particularly at lower ambient temperatures. Also when probably reaching 3.000 rpm or + you will get a lot more white smoke. The latter is more related to excess of force required to the engine. In a water cooled exhaust, is quite difficult to distinguish white smoke normal from white smoke abnormal.

In my view, if the amount of white smoke is huge at cruising speeds, and you dont get overheating, do not loose water refrigerant, the engine doesn t stop, nor rattles, it may indicate that:

1. the propeller is requiring too much force to the engine. This may be a question of the size and pitch of prop, or

2. The engine could no longer cope with the force required by the prop because i.e. lack of compression.

Regards