1987 Mercruiser 260 5.7L 350 - will this San Juan closed cooling system work?

[Blueghost924]

Hi, a guy is selling a San Juan Engineering fresh water cooling system on a local ad. He gives little info, except that it should work on most Mercruiser systems. The other tidbit is that the local marine repair shop said it should work on most Mercruiser systems and they can install it (of course they would).

I don't have the model number, but just by looking at a couple of pics, can anyone tell if it would work on my system? Or other thoughts? Other than adding the heat exchanger and expansion tank, I'm sure there would be other modifications I would have to make to my engine cooling system.

 

[Bondo]

He gives little info, except that it should work on most Mercruiser systems. The other tidbit is that the local marine repair shop said it should work on most Mercruiser systems

Ayuh,.... With the info provided,.... it Should work,......

 

[Scott Danforth]

Here is the issue with putting a hx on a 30 year old motor.

If you have ever been in salt, your block and heads already have rust on the inside. So adding a heat exchanger will only plug up the heat exchanger.

If you have only been in fresh water, you have to pull the heads off and flush out the water jacket from 30 years of debris and sediment or it will plug your heat exchanger

That is an old design. I only see a single inlet and outlet for raw water, so it may be for an inline 6

Just out of curiosity, how much are they asking for the $100 used heat exchanger

 

[Blueghost924]

Here is the issue with putting a hx on a 30 year old motor.

If you have ever been in salt, your block and heads already have rust on the inside. So adding a heat exchanger will only plug up the heat exchanger.

Thanks for the info guys...and I'm glad I'm asking before just spending. Yep - I live in the Virginia Beach area near the ocean...so it's definitely a salt water boat and engine. I bought the boat/engine last year and rebuilt the top end earlier this summer (including a new aluminum bronze coated intake), The heads were taken off and I sent them to a professional head shop for overhaul. I've had the engine out in the ocean about 6 times this year and have religiously flushed it with fresh (garden hose) same day when I got back...and making sure it got up to temp. The previous owner did say last year they ran it in salt.

Sounds like overall, I may need to hold off installing any fresh water cooling system?

For this particular one, the guy is asking $500 for the entire thing...which means it may be overpriced!

 

[Scott Danforth]

I would simply run your boat and have fun.

When you replace the motor, put a HX on it then

 

[Blueghost924]

Thanks Scott.

For what it's worth, I looked at it, and its a San Juan Model SJEC09, and it came off an inline 6. The seawater inlet and discharge are on both ends of the HX and the connections look smaller than my SW inlet hose from the transom.

I think I'll pass...