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-   -   Converting open loop to close loop (https://www.offshoreonly.com/forums/do-yourself-boating-budget/204887-converting-open-loop-close-loop.html)

OhioRiverCigarett 03-14-2009 05:29 PM

Converting open loop to close loop
 
I have a old cigarette open loop cooling system that I am thinking about converting to a closed loop system. Has anyone converted there old engines over?

Zackman 03-15-2009 08:01 AM

I thought about doing this at one time... The problem as I understand it, is once the internals of the engine have been exposed to raw water cooling scale and rust develops. This rust and scale will quickly clog your new closed cooling system, particularly the heat exchanger.

Boomer35 03-15-2009 09:11 AM


Originally Posted by OhioRiverCigarett (Post 2821268)
I have a old cigarette open loop cooling system that I am thinking about converting to a closed loop system. Has anyone converted there old engines over?

hey-

post some pics of the cig, i think its my old mans old 33, white with a red stripe?

have you done any updates?

Audiofn 03-15-2009 06:52 PM

What Zackman said. They do make some flushing stuff now but I have no idea how well it works. I guess it all depends on how often and well the motor were flushed after use.

Thunderstruck 03-15-2009 08:55 PM

I converted raw water cooled 500HPs with aluminum heads to closed loop cooling for the motors. Works great. The blocks were 7 years old run in salt/brackish water when I did the conversion. Mostly homemade with heat exchangers from SeaKamp.

PM me and we can discuss if desired.

rjr 03-15-2009 10:09 PM

My 382 with 500HP's are the first RWC motors I have owned. I wanted to convert them to FWC but Jason @ Performance Marine at Lake George didn't see the point as long as you flush them out religiously. He has a lot more experience than I do so I have been going with his suggestion.

My experience with FWC cooleded motors is that it works great, is incredibly easy to winterize, and when the exchangers get clogged you remove two bolts and run a piece of wire through the tubes. No big deal. However I understand that that with more than 200 hours a combination of rust and antifreeze forms glop that clogs internal passages so is not recommended in used motors. That is backyard scuttlebutt and not something I have any proof of so take it for what its worth. But if someone has any expertise in the matter I would like to know the truth.


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