installing closed cooling system

[rbh]

This winter I have to pull my motors and legs (merc 260s and mr legs) to replace the transom gaskets and while at it I was going to flush out the blocks of crud.
Now my thoughts are of installing closed cooling system if affordable.
any thoughts.
thanks
Rob

 

[Knightgang]

Re: installing closed cooling system

Why would you want to?

 

[zbnutcase]

Re: installing closed cooling system

Expect to pay about $600 ea for the kits, plus install if not doing it yourself. Affordable? Only you can answer that. 'nutcase

 

[JustJason]

Re: installing closed cooling system

you don't want to install a closed cooling system on a block thats already been in service. The heat exchanger will clog constantly.

 

[zbnutcase]

Re: installing closed cooling system

I have installed MANY kits on used engines and you know what? Not a single clogged heat exchanger! 'nutcase

 

[HT32BSX115]

Re: installing closed cooling system

This winter I have to pull my motors and legs (merc 260s and mr legs) to replace the transom gaskets and while at it I was going to flush out the blocks of crud.
Now my thoughts are of installing closed cooling system if affordable.
any thoughts.
thanks
Rob

It sort of depends on how many hours are on the engines. The "rule-of-thumb" is around 100hrs of salt water use. after that the blocks and manifolds usually have enough scale in them that they *could* cause heat-exchanger obstruction if the "scale" begins sloughing off once you switch to 50/50 AF.

I did my 1997 454 with about 125 hours of fresh water use but before I did I removed all the core plugs & circulating pump and then flushed the block EXTENSIVELY though every hole.....I also flushed the manifolds.

I got a LOT of "stuff" out of them......... some rust flakes, a lot of sand and other debris. Some of the debris was almost up to the level of the drain plugs in the block (indicating that maybe a block should be flushed once in a while to just get some of the debris out so it doesn't prevent draining for winterization!)


If your engines are not new and have been used in salt more than 100 hrs,

It *may* not be advantageous to install closed cooling.

Speak to the guys at San Juan Engineering in Bellingham, Wa. Understand that they are trying to sell you a system but they also want you to be happy with it.

I bought my system from http://www.oceaneastmarine.com/ It was shipped directly from San Juan in Bellingham.


Cheers,



Rick

 

[rbh]

Re: installing closed cooling system

Thanks Guys,
The boat origanaly came from portland oregon, were it saw both salt and fresh water.
We have been running it in fresh water the past 3 years.
rob

 

[bruceb58]

Re: installing closed cooling system

I was going to do the same with an engine that had 100 total hours of which 75 were salt. The guys at San Juan talked me out of doing it.

 

[Knightgang]

Re: installing closed cooling system

Thanks Guys,
The boat origanaly came from portland oregon, were it saw both salt and fresh water.
We have been running it in fresh water the past 3 years.
rob

If you are running primarily in Fresh Water now, leave it a raw water system...

 

[Don S]

Re: installing closed cooling system

Having done this conversion on about a dozen boats over the years, all salt water boats, I had about a 50% success rate, or is that failure rate.
The rust and scale in the engine plugs up the heat exchanger, and the coolant side can't be cleaned out like the raw water side can.

 

[dan t.]

Re: installing closed cooling system

I converted from a fresh water cooled block only to a full closed system.However,I cleaned out the manifolds with muratic acid before the new system went on,5 years and still working good

 

[wca_tim]

Re: installing closed cooling system

I converted from a fresh water cooled block only to a full closed system.However,I cleaned out the manifolds with muratic acid before the new system went on,5 years and still working good

that's what I was thinking.. if you flushed and backflushed very thoroughly and also really hit it hard with hydrochloric acid (dissolves rust fast but iron only very slowly) it would be a much higher success rate...

sorry hydrocholric acid = muriatic acid

 

[jaxnjil]

Re: installing closed cooling system

i need to go look at the shop manual to make sure but have this question.

how will flushing the manifolds do any thing for a closed system? doesn't the raw water dump and exit pretty much the same in both? does the anti freeze in the closed even run in the manifolds?

 

[stroyer]

Re: installing closed cooling system

i need to go look at the shop manual to make sure but have this question.

how will flushing the manifolds do any thing for a closed system? doesn't the raw water dump and exit pretty much the same in both? does the anti freeze in the closed even run in the manifolds?

If its a full system the manifolds is cooled with anti freeze.
then its only the risers there are cooled with raw water.

 

[circuit19]

Re: installing closed cooling system

Now I thought that if you were going to a closed system you would need to go to a car exhaustlike manifold set up. Ofcourse I don't know squat about boat's but if it's a closed system can't the manifolds that these open systems have be tossed and replaced by something like headers? I only ask cuz I've found that replacing these OMC manifolds cost is ridiculous.

 

[stroyer]

Re: installing closed cooling system

Now I thought that if you were going to a closed system you would need to go to a car exhaustlike manifold set up. Ofcourse I don't know squat about boat's but if it's a closed system can't the manifolds that these open systems have be tossed and replaced by something like headers? I only ask cuz I've found that replacing these OMC manifolds cost is ridiculous.

The manifolds will be too hot to a enginecompartment, but if the engine is in the free like dragboats i think you can use dry exhaust.

 

[jaxnjil]

Re: installing closed cooling system

If its a full system the manifolds is cooled with anti freeze.
then its only the risers there are cooled with raw water.

i see now. i looked and see if you use the stainless steel block off plate the antifreeze is circulated thru the manifolds and sea water exits thru riser.
other wise could also be plumed like normal raw water cooling with just antifreeze in block and heat exchanger.
thanks for reply stroyer

 

[stroyer]

Re: installing closed cooling system

U R Welcome.