Marinette Boat Forum

This is a long shot.

The raw water cooling version of the '68 to "70something has a thermostat I've seen here referred to as the "barrel style". The so-called barrel rides on a lip seal as it opens and closes. I have one that begs for replacement. I haven't removed it yet because I can't find out what to replace it with and a leaking seal here is probably better than a missing seal.

Anyone have any experience with this?

Skye

The raw water T-stat is specific, as it opens at 140* F, unlike a car at 180-195*F. DO NOT replace it with an automotive version ! Chrysler part number is 3527765, if you google it, you will find many vendors that carry it. Not sure if it crosses into a NAPA number or a Stant. The stat's housing gasket is however all the same. Hope this helps.

Thanks Jim,

I have the proper thermostat. The housing has a lip seal in it that the chrome "barrel" of the thermostat slides in so that opening the thermostat turns the housing into a valve. This thing is a serious piece of engineering. It will seal so tight that I expect I need to remove it when I winterize. Anyway, it's the lip seal I need to source. The seal to the engine is a Felpro gasket available at NAPA for about $2.

I talked to the thermostat manufacturer. It a Caltherm CT2208-38. They recognize the part number but that's as far as it goes. I found the 1968 thru '74 parts manual for the LM318 and it does not show the lip seal that is inside the housing as a part, only the housing. I figure this is a dead end. Something could be made to work I assume by pulling the seal and reverse engineering it by the dimensions. However, the OEM housings are still on the shelf at various places for around $100 and have the seal installed. If the elastomeric material isn't past it's best by date it should be fine for another 50 years.