Changing to Closed Cooling, Merc 5.7, Input Please

[Alex_AGB]

I've decided to go to closed cooling on my SeaRay 5.7L. My local Merc dealer wants $1500 for the kit. Other than the heat exchanger it looks like it could be easy to piece my own kit together for much less then $1500. What do you guys think?

 

[Bondo]

Re: Changing to Closed Cooling, Merc 5.7, Input Please

Ayuh,... Is this a New motor,..?? Original motor,..?? Run in Saltwater,..??

Search up San Juan Engineering... They're a popular aftermarket system provider...

 

[Don S]

Re: Changing to Closed Cooling, Merc 5.7, Input Please

On a 10 year old engine I wouldn't waste my time.
All the corrosion and rust starts flaking off the engine and plugs up the new heat exchanger, on the side you can't get to to clean.
That's why OEM recommends converting with in the first 125 hours or first year or leave it raw water cooled.
If you do decide to change it anyway, there are aftermarket companies like SanJuan Engineering that make kits a lot cheaper than the OEM kit from Merc.

 

[Alex_AGB]

Re: Changing to Closed Cooling, Merc 5.7, Input Please

It's a 5.7 TBI fresh water boat with 130 hours on it. I'm going to be using it in salt water starting this year.

 

[Bondo]

Re: Changing to Closed Cooling, Merc 5.7, Input Please

Ayuh,.... Just Guessin',... SJE kit,+ your labor otta be about 1/2 what you were quoted...

 

[HT32BSX115]

Re: Changing to Closed Cooling, Merc 5.7, Input Please

I got mine from these guys for about $700 a few years ago.....It was shipped directly from San Juan in Bellingham Wa though.....


Cheers,


Rick

 

[Alex_AGB]

Re: Changing to Closed Cooling, Merc 5.7, Input Please

I got mine from these guys for about $700 a few years ago.....It was shipped directly from San Juan in Bellingham Wa though.....


Cheers,


Rick

Thanks Rick, I?ll be calling them up on monday! They have awesome pricing, less than 600 bucks for block only closed cooling and $750 for full closed cooling!
For the sake of 150 bucks do you guys think it's better to go with the full closed cooling system as apposed to the block only closed cooling?

 

[Bondo]

Re: Changing to Closed Cooling, Merc 5.7, Input Please

For the sake of 150 bucks do you guys think it's better to go with the full closed cooling system as apposed to the block only closed cooling?

Ayuh,... Absolutely....

 

[HT32BSX115]

Re: Changing to Closed Cooling, Merc 5.7, Input Please

Ayuh,... Absolutely....

Absolutely absolutely!!

I LOVE the system! It REALLY makes winterization a "snap"!!


Now I guess I should say that I added closed cooling to a roughly 10 year old fresh water engine. (against the recommendation of the people in the know)

I had the engine out and I extensively flushed the block with all the core plugs removed...... and manifolds before I installed it.

I got a SIGNIFICANT amount of loose rust, scale sand, and other debris from both the engine and manifolds.

So far no problems..... I am going to flush everything again this summer and see what I get.

The San Juan Tech support guy told me that I would be ok....(OF course he's the one selling the kits!!!) We'll see I guess.....


Just be aware that you might be removing the heat exchanger to clean it out if you don't THROUGHLY flush everything! (and you may anyway)


Good luck...


Rick

 

[skargo]

Re: Changing to Closed Cooling, Merc 5.7, Input Please

Cleaning the HE is a part of closed cooling maintenance anyway.

 

[scutly]

Re: Changing to Closed Cooling, Merc 5.7, Input Please

this is the system i have. Monitor Products. its been on my boat since new (16 years and a little under 600 hours) with no problems. poking around the net i found it here for $700. dolphin marine

 

[zbnutcase]

Re: Changing to Closed Cooling, Merc 5.7, Input Please

And you could install a inline coolant filter, Summit has 'em and others do too.

 

[skargo]

Re: Changing to Closed Cooling, Merc 5.7, Input Please

And you could install a inline coolant filter, Summit has 'em and others do too.

Interesting. I haven't even thought of one, but now, I must have one! Great idea.

 

[dirtyoldman]

Re: Changing to Closed Cooling, Merc 5.7, Input Please

Interesting. I haven't even thought of one, but now, I must have one! Great idea.

That would work, but be aware that coolant filters are typically bypass filters, NOT full flow filters. If you install it in series you will restrict coolant flow too much. It has to be installed in parallel to something that causes a pressure drop. I installed them parallel to the heater core in diesel trucks.

 

[skargo]

Re: Changing to Closed Cooling, Merc 5.7, Input Please

Thanks dirtyoldman,
I will keep that in mind!