How Important is the thermostat?

[NatySailor]

I have an early model Atomic 4 with no thermostat installed. I recently cleared up a long-time overheating issue and now my engine is running nice and cool -- perhaps too cool. So now I'm reading about thermostats.

My question is: How important is it to have the engine running at the proper temperature? For the most part, I just motor to the end of my channel (less than 10 minutes of motoring) and then sail away. Same thing when I'm coming home.

I've also decided to keep my boat in the water this winter, so when I motor out my channel the raw water coming into the boat will be 50 degrees or less.

I think I'll install a thermostat eventually, but given everything I've mentioned above, how urgent is it? Could I damage my engine by sucking up icy cold Chesapeake Bay water, or will it just not run as well?

[Marian Claire]

Do you have the Dole T-stat housing?
Dan S/V Marian Claire

[joe_db]

Your engine is going to suffer no matter what with 10 minute runtimes. Indigo makes a thermostat you can add to an old engine, but that won't do too much in 10 minutes. The oil will get more and more contaminated since it never gets hot enough to boil off the water that builds up.
I would suggest either buying a thermostat or making a control valve of some kind and running the engine for an hour every few weeks hard enough to heat the oil up.

[NatySailor]

Do you have the Dole T-stat housing?
Dan S/V Marian Claire

Not sure... I'm just starting to educate myself on t-stats.

Perhaps the attached photo will make that more clear. There's a fitting at the aft end of the manifold that accepts the temperature sensor and leads to the exhaust.

[joe_db]

Looks like the answer is no.

[Marian Claire]

I think Joe is correct in both his posts. Here is an option. Second diagram.http://www.moyermarine.com/forums/showthread.php?t=4267
I have found the re circulation loop with a control valve to be the best option for me.
Dan S/V Marian Claire

[joe_db]

Do be very careful with any temperature control idea on a RWC engine that enough water gets fed into the exhaust. You do not want any way to do 100% recirculation.