Closed cooling system worth the money?

[wakeboarddude]

Hello. I just recently bought a 1988 Malibu Sunsetter with 5.7 mercruiser direct drive. The boat has 580hrs on it. From what i was told and the appearance, the boat has never been run in salt water. As much as I'd like to keep it that way, the salt chuck is only 10 mins to launch so I am out there alot. Since i bought it I have been in the salt twice.

My Question... Is it worthwhile at this point to install a closed cooling system?

The cost, $600-1000 CAN. this is just the block cooling only. I'm pretty sure I can install it myself so that keeps labour costs down.

I keep the boat trailered so it will be thoroughly flushed after every use. i understand that no matter what you do manifolds have only a short lifespan in the salt anyways. I have read mixed thoughts on this topic and was even told by a co-worker quoting a mechanic " I cant stand all these guys that waste their money on these closed cooling systems"

So in my situation, what do all you experts think... should i just save my time for riding and money for fuel?
Thanks all

 

[HT32BSX115]

Re: Closed cooling system worth the money?

Howdy,

Unless you're going to replace the engine with a new one, you're wasting your time. The rust that is already inside the block will clog the heat exchanger in short order.

If you were going to replace the engine (or it had less than 100hrs on it..) Then it might be worth it. I would also include the manifolds too in that case.


Cheers,

Rick

 

[JJJ]

Re: Closed cooling system worth the money?

While many don't like to do it after 100 hrs or so, I did it on my 4.3 Cobalt last year and it was by far the best thing I could have done.
I only use the boat 1-2 weeks a year and in salt, even flushing (using salt away) it was rusting quickly due to sitting.
I would rec. if you are going to do it, replace the manifolds and go with a full system AND keep an eye on the temp guage and/or clean the heat exchanger a few times early on to see if it is catching rust debris.
I put strainers on my system to catch any rust, checked them this year and there was almost no rust in them at all. (I had to change a cyl. head due to cracking from rust blocking a port prior to putting the closed system on. At that time I blew the block out really good and put new manifolds/risers on.)

On the Plus side, it makes winterizing nice too

With the full system only my P/S cooler, heat exchanger, and risers see salt

 

[HT32BSX115]

Re: Closed cooling system worth the money?

When I did my 454, I used a closed cooling system from these people It was a "full" system.

My engine had just a little over 100 hrs on it and I had all the core plugs removed.

I removed a LOT of rust and debris from the block and manifolds. It took me quite a while to get it all out.

Now, I would not have a boat that didn't have closed cooling. The engine will run better, and last longer than ever before.


Regards,


Rick

 

[WizeOne]

Re: Closed cooling system worth the money?

Heeding all the caveats above, I would go for it, especially in freezing climates and or saltwater use. Mine only does the block because my log style exhaust manis will not accomodate it.

Even still, it's easy enough to pull the plugs on the mani's and drain them. I installed T's, with threaded hex plugs, on the mani feed lines, so I just back out the plug, insert funnel and fill the mani's with a 25% strength anti-freeze.

At the beginning of the season, I drain the antifreeze back into the bottle and reuse it the next year.

Another bonus is that if you are carbureted, you can install a 180 deg thermostat. Marine motors are run much cooler than is ideal soley for the purpose of keeping salt from plating out inside the motor. Your motor is much more efficient when running it at 180 and mine pegs at 180 whether at idle or WOT.

Unfortunately, if you have EFI this is not advisable because the ECU is looking for the stock thermostat temperature in figuring the air/fuel ratio.

 

[wakeboarddude]

Re: Closed cooling system worth the money?

Thanks all. I guess I'll spend the money. No real downsides to installing the system, I'll just have to be sure the rust won't clog the heat exchanger. Just spent the morning on the water and I am lovin my new boat!

Happy Cruising!

 

[mylesm260]

Re: Closed cooling system worth the money?

I think the rust clogging the heat exchanger issue is over-blown.

Install a strainer, check it often, and keep an eye on your temp gauge, you will be fine.

It's not like the heat exchanger is going to go from 100% flow to 0% right away.

If rust gets in there, and starts clogging it up, you will most likely notice some slightly higher than normal engine temps at high load. Then you will know that the flow through you're exchanger has been reduced, and it's time to drain your coolant and back-flush it.

 

[wca_tim]

Re: Closed cooling system worth the money?

the only real downside I can see is more weight...

 

[wakeboarddude]

Re: Closed cooling system worth the money?

Is there a specific strainer I can install or is it something i have to rig up?

More weight isn't an issue as we're wakeboarding and loading the boat with ballast anyways.

 

[JJJ]

Re: Closed cooling system worth the money?

I used standard brass plumbing strainers 1" npt I think, they are mounted on top of the manifolds - between the manifolds and heat exchanger on each side.

If you use them, I would recommend you remove the removable cap BEFORE installing them and add teflon tape to the threads. Some of the caps are super tight and would be a pain to remove installed.

I also removed the plugs in the strainers and put on there a hose with ball valve - just in case they got plugged up the first time out. Mind you my time outs are for a week straight on vacation. Then I could just open the ball valve and flush any major debris.

hxxp://www.monitorpro.com/products/item.php?i=3&f=14&c=9

this is the kit I went with.