Is it hard to convert inboard engine to antifreeze?

[car5car]

From car mechanic's point of view running salt water thru engine is pretty stupid idea. I was thinking about converting to antefreeze and it seems to me that I only need to buy stainless radiator (sea water/antifreeze)and couple hoses. Am I right?

[Don S]

It's a little more involved than that, The heat exchangers as they are known are make of copper with a tube bundle and both a raw water side and an antifreeze side. The thermostat housings are also different.
What type engine are you wanting to convert to a closed cooling system?
You do realize, after an engine has over a 125 hours or basically 1 years use, converting to a closed cooling system is not recommended.

[chuck in WA]

I have an aftermarket system on my 1985 SeaRay 3.0 made by these folks:

http://www.orcamarine.com/

It was already installed on my boat when I bought it 3 years ago, so I'm not sure how long it's been on there, but I haven't had any trouble.

Don S - why is the conversion not recommended after 1 year? The damage has already been done?

[Haut Medoc]

The rust & scale from running raw water will dissolve & clog the heat exchanger......
That said, if you were willing to have the exchanger boiled out periodically & change the coolant as well, you might be able to extend that time frame on an engine that was run strictly in fresh water....
If it were run in salt water I wouldn't waste my time if it were past the 1 year/100 hour threshold.........JK