Fresh water cooling

I just purchased a 19' Stingray (1998) with 100 hours on the Mercruiser 4.3 I/O engine. Boat has never seen salt water and been stored indoors all of its life. I will be using it in brackish water. I am considering installing a fresh water cooling system to eliminate salt issues. Any sugegstions on what manufacturer to buy? Also the boat will be stored in Virginia in an unheated, but well insulated garage. I am assuming that I still need to winterize?
Thanks

Re: Fresh water cooling

I think I would rather go all the way with the system that cools the block and the manifolds.

Re: Fresh water cooling

Going to be expensive... but it may be worth it to you. Another option is to flush it when you come off the water on the muffs. As to winterization, there are different procedures for each cooling system type, but some items that are universal. Right now you are using raw water, if you are done for the season, winterize now. Personally, I have another month or two of Fall cruising to do!

V

Re: Fresh water cooling

jsdiii said:

I think I would rather go all the way with the system that cools the block and the manifolds.

Click to expand...

I did a similar thing (full system) with my 1997 454 (120hrs since new) The system came from Ocean East Marine (San Juan System) http://oceaneastmarine.com/freshwater.html

I think it was about $750 back in 2006.

One thing to consider is that your block and manifolds will have a fair amount of rust in them and that rust can and will break off and possibly clog the heat exchanger if you don't do something to remove as much as possible.

When I installed mine, I had the core plugs out of the block and the circulating pump off.

I was able to thoroughly flush the block and manifolds to get most or all of the loose rust flakes sand and other debris out of it (the block) etc. You cannot of course, get it all but you can get a LOT.

So far, I have had no coolant flow problems in the heat exchanger.

After running it for 4 years or so, I have not yet removed the heat exchanger and opened it up to see if there's any rust or other debris clogging the tubes etc... I used DEXCOOL mixed 50/50 with distilled water for coolant.

It works great! I will never go back to raw water cooling.


Regards,


Rick

Re: Fresh water cooling

Should I have rust in the block and manifolds now even if the boat was never run in salt water? Is there any easy way to know, or flush it out? Should I scrap this idea based on the motor's age (only has 120 hours)? As I understand it... raw water will cool the closed system water in the heat exchanger and be diverted back overboard as normal. Won't it still be necessary to flush the raw water system after each use? LEss often?

The cost looks to run between $800-$900 for the San Juan system which is a lot of money, but I want to avoid replaceing manifolds and risers every three years. That cost is probably equivalent to the Fressh water cooling system cost. Installation doesn't look too difficult.

Much appreciate your advice!

Re: Fresh water cooling

I seem to remember some people suggesting that a year or so and 100hrs(in salt water presumably) is a sort of limit for installing closed cooling.

San Juan Engineering told me that you can successfully install a closed system if the engine is older and has been run in fresh water.

The (unprotected) cast iron components of an engine (block, manifolds, risers etc) begin rusting immediately.

There WILL be rust in the manifolds and block. I flushed out a lot (including sand)

Even after you install closed cooling, you should ALWAYS flush a salt water cooled engine (or RAW "side" of a closed cooling system....and rinse everything else!) every time it's stored or parked. You don't need to replace the coolant more than about every 5 years or so if you use the long life stuff (DEXCOOL etc)....

You will still have to replace risers. They are always raw water cooled.

Fresh water manifolds can last 20 years. Closed cooled manifolds can out last the engine (and boat!)

I had the engine out when I installed mine. Installation was a "snap" and San Juan Tech Support is pretty good.