I am going to repower a 6.2 Mercruiser with freshwater cooling. A new engine with fresh water cooling is 2k more and I put about 100 hours on her a year, is it worth it?
I appreciate any suggestions

If salt water use, yes. Other wise no.
run on hose before put to bed and your golden.

Like stated, depending on where you boat. Salt OR brackish water I would get Closed Cooling. It will also help with resale value and open up boat to more possible future buyers. .

i talked to Mitchigan Motorz at length about this when I put 2 new 350s in my boat. I boat near Baltimore, MD. According to info I could find, where I boat is only about 6 Parts per thousand salt. And I flush after every run. Mostly to clear out anything like mud and crap.

We decided that as long as the exhaust parts (which are usually open cooled anyway) are replaced every 5 years (my 20 year old original ones killed the original engines by previous dumbass owner). it would be fine, and I'd most likely get 10-20 years out of the engines anyway, with full open loop. Much longer than I plan to keep the boat anyway...

So if you're not that salty - I wouldn't bother. just stay on top of manifolds and elbows. I plan for every 5 years now. So. fall 2025 for me.

Would you run salt water through your car’s cooling system?
Given that you have the choice, why would you run it in your boat’s engine?
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RR

Doesn't closed cooling also have he benefit of more consistent operating temps?

The closest thing you're going to find to fresh water is what you'd catch in a clean bucket outside after a rainstorm . Is the 'fresh water' that any of you boat in anything remotely like that ?
No , it's full of all sorts of dissolved solids and who knows what else .
Although I'd take any of your versions of fresh water over this saturated brine over here I'd still go with closed cooling because once you're running that anti-freeze mix you can also forget about any reactions to indifferent metals used in the construction of your engines.
Yeah , I'm a big proponent of fresh water cooling .

I like the added protection of overheating as well. How many times have you sucked something up and ran the block dry? By the time you realize it you have massively overheated it and possibly done head damage Closed cooling you at least have anti freeze in the block.

I have a nice clean Chrome system off of a Volvo 7.4 BBC complete with brackets I will sell for $450 plus shipping. You will need hoses and thermostat housing (I think).
Send me a PM if interested.

CC is single handedly the best money I have ever spent on my boat. I sleep great knowing that dissimilar metals in the block/heads/intake are only being covered in non-corrosive antifreeze and distilled water. No brainer to me.....