Can you explain the cooling system of my 165 mercruiser?

[Milemaker13]

I am new to the inboard/outboard drive system, and want a better understanding of how it all works. I understand the cooling system consists of a seawater and fresh water section. That makes sense, like exchanging your air cooler radiator in a car for a water cooled heat exchanger on the boat.

But, I do not see the typical overflow bottle and pressure cap like on a car. How would I fill the fresh section? Should I use water or anti freeze?

Any other info you have , like how the water flows, Id be interested in reading.

 

[Bondo]

Ayuh,.... In yer other thread you say it's an I-6 motor,... Chances are, you don't have closed coolin',....

Just the impeller in the drive that provides raw water to cool the motor, which is dumped out through the exhaust,....

 

[Milemaker13]

OK! That's a start, lol. I didn't see an exchanger like the ones pictured in various lit. and was wondering how it all worked.
So no fresh water section, just sea water thru the impeller.

 

[achris]

If you have a heat exchanger, it will be on the port side, under the manifold. Big cylinder thingy. About 3" diameter and 20" long...

 

[Fishermark]

As Bond-o points out you do not have (more than likely) a heat exchanger. Also, for future reference, you might want to start giving a little more information on your motor / drive combo instead of simply "165 Mercruiser." Not busting your chops! There are a couple of engines that are identified as a 165 - and they are worlds different. The pros like serial numbers - but at the very least identify it as a straight 6 or something similar. Let us know what outdrive you have as well. (This engine is the same as a Chevy 250 engine).

 

[Bondo]

As Bond-o points out you do not have (more than likely) a heat exchanger. Also, for future reference, you might want to start giving a little more information on your motor / drive combo instead of simply "165 Mercruiser." Not busting your chops! There are a couple of engines that are identified as a 165 - and they are worlds different. The pros like serial numbers - but at the very least identify it as a straight 6 or something similar. Let us know what outdrive you have as well. (This engine is the same as a Chevy 250 engine).

Ayuh,..... 'n Milemaker got the Right one,.......