Closed cooling system questions.

[vrvokey]

Need help with a heat exchanger add on to a late 80's merc 5.0.I found a guy in the area with a heat exchanger for sale for $125,it looks in very good shape and is clean inside.He says it was on a 455 olds bigblock,it has four ports,2 large and 2 small.I have read some things about half and full closed cooling systems,can anyone explain the difference and what is the best way to plumb it in.We use the boat on a river which is salt water,its not near as salty as the ocean and I'm wondering what the plumbing should be to add the heat exchanger and is it worth it,also what should I look for,common problems with heat exchangers.

 

[vrvokey]

Re: Closed cooling system questions.

Hey

 

[QC]

Re: Closed cooling system questions.

Do you keep it in the water? Most here believe it is not worth it if:

a) it is an older engine and used in salt previously and

b) you can flush with fresh water after every use.

Half system is long block cooling only. Full includes the manifolds.

 

[vrvokey]

Re: Closed cooling system questions.

Thanks for the reply,to answer your questions we don't leave it in the water,it;s in for the weekend mabe 4 or 5 hours each day depending on weather and I always flush it on the garden hose until it warms up and I can't taste any salt in the water coming out of the exhuast(hot water port) on the out drive.So your thinking it's a waste of time and money to switch it.The engine has 420 hrs,nothing ever done to the block and the manifolds and risers were changed at about 300 hrs.