Closed water cooling !! true or false

vanillacc1

Recruit
Joined
May 29, 2008
Messages
2
I have twin 1988 volvo penta v8's aq231a and i was planning on switching to a closed system however i saw the information below, is this correct as there are very few warnings on the sites that sell thease.

"If you own an older boat. You may not be able to install a new Fresh Water Cooling System. The rule of thumb is One hundred and fifty hours of salt water use. And about two hundred and fifty hours of fresh water use. After that. It is probably too late to install a fresh water cooling system without severe damage to your engine. You can perform a quick check: Remove the thermostat housing cover. Then look inside to check for any sign of scaling rust. If you see rust build up. It is probably too late. Engine Blocks are made from Cast Iron. And Cast Iron is Porous! Salt will embed itself in the cast iron and then, if you add antifreeze, the coolant will become thick and cause your engine to overheat.
Source http://www.boatfix.com/freshkits.asp bottom of page.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,454
Re: Closed water cooling !! true or false

I have heard the same. Your new heat exchanger stands a very good chance of getting clogged with an older engine with rust/salt build up. If you do want to chance it, I would not run antifreeze for awhile and do many drain cycles of the coolant water.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Closed water cooling !! true or false

Looking into the thermostat housing will tell you what is inside the intake manifold, not the engine.
The engines are 20 years old. Leave them raw water cooled.
 
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