I'm trying to decide if I spend the money on a closed cooling system or keep open. I have a Domzi Classic 18 and want to be able to run up to an hour at 5000-6000 rpm on a SBC (special build). Is the most efficient/effective cooling for oil etc best with an open system? Thank you

If you boat in fresh water, I'd use the trillion gallon water supply at your disposal. ie: open system.

I've got a built 383 stroker with a closed loop system, manifolds also closed loop. In the 100+ degree heat and 80+ degree water temps it runs hotter than I'd like. I only do fresh water so I've actually thought about removing the system and going open system. Hope that helps.

I would make the manifolds sea cooled. You won't have any issues than.

That's a cheap and easy solution, thanks underpsi68. I bet that would work just fine. I'll add that to my winter upgrades list.

You can't mention Donzi and not post a photo man!!!

BTW, I have a mild 355 going into my 79 18 2+3 and will be keeping the cooling system fresh water cooled.

Ultimately, I landed where you did which is an open cooling system. I did make some rough calculations and could not see any benefit to not leveraging the massive capacitance of an inland lake.

Regarding the Donzi, I will attach a link. My bad. The boat started out yellow... repaired the hull, applied new gel coat and striping, replace stringers and transom, built a splayed 388 engine and replaced Volvo outdrive with a MerCruiser bravo outdrive

The restomod is now complete and have had several thermal runs where I was able to maintain 65 mph on Lake Huron for almost an hour. I think that’s good enough for what I was I was after.

http://s750.photobucket.com/user/dav...=recent&page=1

Sweet ride man!!!

Didn't I see your build on Donzi.org?

Thanks!

Yes, I have details of the build there. I’m planning to sell and do a Classic 22, but with a built BBC

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