White smoke or steam 454

[northern]

We have a 1989 38 Aft cabin with twin 454s with 1400 hours each. The Starboard engine blows white smoke or steam on start up. Does not smell like burnt oil. After two minutes it stops. The Port engine does not do this. Both engines need anti freeze in the plastic expansion bottle very 70 hours may be 1/2 quart. In 200 hrs the port engine used 1/2 quart of oil the starboard 1 quart. Oil is clean and no water in it. Replaced the raw water pump on the starboard and it did not change any thing. Both engines run at the same temperature (heat gun reading on the thermostate 160f boat has 142f thermostats) Cast rizers are the same temperature 90f. The exhaust hoses on the starboard at the hotest point are 130f on the port they are 115f. Sea strainers are clean and the flow rate into them both is the same, based on opening the hull valves when the tops are off the strainers. Water flow rate out the exhausts seems to be the same the water tempurature feels the same. Warm but not hot. The Port looks like it is slightly more some times.
Does any one know what the smoke is and if it is bad or normal?

 

[Nehalennia]

By your description, it's possible you have a blown head gasket.

 

[fc3]

Do a pressure test on the cooling system. Sounds like you have a problem and need to start there.