An
oil cooler is a bit controversial. Some folks it's hard enough already getting the
oil up to temp without one. Sometimes impossible to reach a decent temp with one!
As has been suggested on this thread, an
oil thermostat is one way to address the problem. I don't know if I'm sold on the whole oil cooler thing or not, I don't run one, never needed one. It's certainly another level of complexity for "stuff" to go wrong. Horribly wrong in some cases...
Oil temperature does NOT have to reach "boiling point" to evaporate any moisture within the oil from initial cold start conditions. Simply raising the oil temp to a reasonable level will accomplish the same thing IF you maintain that temp for 30 minutes or so. That's why "short drives" are so hard on motors, water never evaporates. In addition the oil temp you SEE is an "average" of what is in the pan. The actual oil as it flows around the upper part of the engine gets considerably hotter as it comes in contact with the combustion chamber areas. Then mixes with the pan oil and gives up this heat you don't see.