fresh water/closed cooling system

jefflaw35 · Post by **jefflaw35** » Wed Feb 15, 2012 2:11 pm

im looking into this for my 318, since I will the entire boat gutted it seems like a good investment and right time to do it considering I boat in salt water. Any suggestions, pros or cons?? Thanks

prowlersfish · Post by **prowlersfish** » Wed Feb 15, 2012 2:52 pm

Its a good idea , the engine in your boat has it now . If the engine you maybe getting is raw water cooled and been run in salt water it may not be worth it .fresh water/closed cooling engines will run better last longer and burn less fuel as the run at better ( warmer) temp .

jefflaw35 · Post by **jefflaw35** » Wed Feb 15, 2012 3:03 pm

huh?? i already have it? hmmm guess i didnt realize that, but it would explain why the prev owner had 15 gallons of antifreeze on board. motor im getting should be the same, but its coming off of a lake and never seen saltwater thank god. wow that just changed my whole out look, if this motor runs off antifreeze then how could he tell me its seized up from not being winterized? any why is it so seized up. my motor may be good after all

Commissionpoint · Post by **Commissionpoint** » Wed Feb 15, 2012 4:23 pm

It still has water going through it Jeff, its just got a heat exchanger, which is the 'closed' part of the system. If the PO had a bunch of antifreeze on board it might be because the system has some leaks and he had it there so he could top it up. Unwinterized and it will still ruin the engine. From the looks of your pics, you are doing the right thing looking for a decent long block to do a swap with. I realize pics can't tell the whole story, but they do say enough that I think your plan to do a swap is a good one. If you decide to go with a closed system its definately a good idea, as Paul already mentioned. Do expect to have to spend some more money to set it up though. Closed system components are a bit more costly, but worth it in the long run, espescially if you are in salt water some or all of the time.

jefflaw35 · Post by **jefflaw35** » Wed Feb 15, 2012 4:33 pm

so what i have now isnt completly closed?

Commissionpoint · Post by **Commissionpoint** » Wed Feb 15, 2012 4:46 pm

Correct. Raw water circulates through the heat exchanger and associated plumbing to keep the coolant from overheating. Notice there is no radiator and fan assembly. The function of the radiator and fan is replaced by circulating raw water. Am I making sense to you? I'll see if I can find you a simple diagram to look at just in case i am speaking gibberish.

jefflaw35 · Post by **jefflaw35** » Wed Feb 15, 2012 4:49 pm

no its makes sence, i just thought the systems i was thinking about didnt use any water from the ocean, seems pointless to spend the $ if your still running saltwater thro it. unless its just the system that uses the saltwater and not the motor

Commissionpoint · Post by **Commissionpoint** » Wed Feb 15, 2012 4:52 pm

http://www.boatpartsinfo.com/2010/05/ma ... xchangers/

Maybe this helps?

Commissionpoint · Post by **Commissionpoint** » Wed Feb 15, 2012 4:53 pm

jefflaw35 wrote:no its makes sence, i just thought the systems i was thinking about didnt use any water from the ocean, seems pointless to spend the $ if your still running saltwater thro it. unless its just the system that uses the saltwater and not the motor

Exactly. The coolant (antifreeze) goes thru the block, and the water is used to cool off the hot antifreeze after its been through the engine.

jefflaw35 · Post by **jefflaw35** » Wed Feb 15, 2012 4:59 pm

weird, then why would you have to winterize an enigine that uses antifreeze? that maybe a dumb ???

Commissionpoint · Post by **Commissionpoint** » Wed Feb 15, 2012 5:03 pm

The heat exchanger will get ruined from expanding water if it is left full and it freezes. Also the other plumbing that has water in it needs to be drained and winterized properly or the same thing will happen to those too. (Manifolds, etc)

jefflaw35 · Post by **jefflaw35** » Wed Feb 15, 2012 5:05 pm

i gotcha now, thanks. im liking the idea of that keel cooler system, im sure it pricy but it looks like all fresh water, never takes in raw water for anything

rcamaine · Post by **rcamaine** » Wed Feb 15, 2012 5:06 pm

Jeff - you still have to winterize the salt water loop - i.e. make sure it is drained and often filled with aniti-freeze. My yard does that for me here in Maine so that if there is an issue - they are responsible.

The closed (fresh water/anti-freeze) loop is already set for winter. I do have them flush that though from time to time, just like a radiator flush in a car.

Commissionpoint · Post by **Commissionpoint** » Wed Feb 15, 2012 5:07 pm

jefflaw35 wrote:i gotcha now, thanks. im liking the idea of that keel cooler system, im sure it pricy but it looks like all fresh water, never takes in raw water for anything

Keel coolers are nice, but they aren't really for your particular application.

jefflaw35 · Post by **jefflaw35** » Wed Feb 15, 2012 5:16 pm

so all this leads me to wander why i cant drop an old ford radiator with and electric fan down there, think its possible?