PDA

View Full Version : Closed cooling



smokediver
04-07-2015, 11:02 PM
Hey guys , I would like to get a few opinions on converting my 502 mag mpi to closed cooling. It has about 250 hours , a 2001 model. I remember Tidbarts motor locking up on a trip and I believe it was in part due to saltwater eating away at the intake manifold. My plan is to do a long trip in fresh water , pull the intake and check for corrosion and then to install a half closed cooling system. I am sure I will have to replace the coolant a few times but hopefully it will hold any corrosion in check. Any thoughts ?

BUIZILLA
04-08-2015, 07:05 AM
i'm getting ready to do the exact same thing on a 502-415 myself.. within a week or so

we'll talk :yes:

Morgan's Cloud
04-08-2015, 07:10 AM
The stock Merc kit for that engine is quite a simple and clean installation and works fine.
I think most of the issues raised will be how much flushing / time will be needed to completely clear all of the salt in the pores of the iron out .

If you have the stock cast iron exhausts , that's what you have to worry about. I replaced mine with Hi-Teks at 67 hours , about 2 years on them since new , and they were just starting to show salt penetration in the metal and an iffy riser gasket.

FWC is great to have .

gcarter
04-08-2015, 01:36 PM
On larger, more powerful engines, 1/2 systems are the only way to go. Otherwise the HE gets pretty big.
I really like electric circ pumps. Meziere makes some nice large capacity for both engine mounted and remote.
The brand I used is from Monitor Products http://www.monitorpro.com/products/category.php?c=20&f=14
built in Brooksville, FL.
This is a cheaper place to buy the Monitor systems: https://www.perfprotech.com/high-performance-fresh-water-cooling-systems/category/1511 .
If you buy from these folks, they are drop shipped from Monitor here in FL.

There's a bunch of others. I like the Monitor system because it includes a HE mounted thermostat and the engine cooling runs wide open all the time.

smokediver
04-08-2015, 01:45 PM
Thanks for the info George. I was also looking at a kit from center state engine in brooksville. Maybe the same one. They are asking just under 800 for a complete half kit. I just did a half ditch run from Franklin lock to the fish camp and back. I put in on the east side of the lock so it was all fresh water. I am sure there will always be some residual but hopefully 5 hours of runtime is a good start. Jim , give me a ring at 239-777-2631 and let me know how your conversion goes !

BUIZILLA
04-08-2015, 02:13 PM
I haven't bought anything yet, still shopping :)

JayZ
04-08-2015, 06:29 PM
I used the kit George mentioned. Very stable temps at around 165. Pretty straight forward install but mine was on a new engine. The H.E. is pretty big...

Tidbart
04-09-2015, 09:59 PM
Just as a point of information the weak point isn't the iron it is the aluminum intake manifold.

smokediver
04-10-2015, 08:46 PM
I remember you mentioning that Bob. I put a set of EMI manifolds on and am now turning my efforts to check the bottom of the intake. Hopefully it's still in good shape !!

Morgan's Cloud
04-11-2015, 01:02 PM
Just as a point of information the weak point isn't the iron it is the aluminum intake manifold.



Can anyone explain why a manufacturer of marine engines would use dissimilar metals in its construction , aluminum nonetheless , and NOT sell it as FWC only from the factory ?

(I've wondered this for a long time )

joseph m. hahnl
04-11-2015, 10:38 PM
Can anyone explain why a manufacturer of marine engines would use dissimilar metals in its construction , aluminum nonetheless , and NOT sell it as FWC only from the factory ?

(I've wondered this for a long time ) I suspect it's optional because not every boat is going to run in the salt. You don't really need closed cooling if your running in fresh water. I think it's more the boat factory that fails to install the cooler package. My old 350 Mag was a closed cooling conversion. worked great for years. That full cooler is now on the Phoenix 400. The intake manifold is still alive and I'm using it in my 350 Mag RHR build for my cruiser. That build also has a full cooler and I'm changing from 3.0 logs to 4.0 center outlets with stainless risers. :kingme:

gcarter
04-12-2015, 09:15 AM
Can anyone explain why a manufacturer of marine engines would use dissimilar metals in its construction , aluminum nonetheless , and NOT sell it as FWC only from the factory ?

(I've wondered this for a long time )

Steve, I think the days of that are over. W/the advent of all aluminum, injected, catalyzed engines, closed cooling is required for a lot of reasons.
Let's all get used to coolers, newer controls, higher operating temps, etc.

mattyboy
04-12-2015, 10:20 AM
Steve, I think the days of that are over. W/the advent of all aluminum, injected, catalyzed engines, closed cooling is required for a lot of reasons.
Let's all get used to coolers, newer controls, higher operating temps, etc.


Most of the VP offerings have FW cooling they seem to embrace technology VVT, computer control , automatic trim control, cruise control

Morgan's Cloud
04-12-2015, 01:13 PM
The idea that not every boat is going to run in salt water has crossed my mind a few times before . The problem is that only 3% of all the water on earth is fresh water .

Just as a reference , when we ordered the 502Mag for the Mag 25 we already knew we wanted the FWC option and the supplier thought it was an excellent idea although he never mentioned anything about an aluminum intake .
It was probably more to do with the fact that he knew we were going to take care of it , especially considering that we're in some seriously salty water over here .

When I ordered the Volvo 5.7Gi for the St T I wanted FWC but I didn't think it was going to fit in the very limited space under the engine box . The supplier said that he ordered all of his engines with FWC whether the customer specified it or not.
I think I can recall him saying something about the aluminum intake manifold that Volvo used as being a big part of the reason.
Incidentally , it is mentioned in the voluminous Volvo owner's manual that they use a special alloy manifold of their design on that engine , but there's no mention of such a critter in the 502 handbook.

Otherwise, I think you're right George, and Matty , as the engines continue to evolve into ever more high performance and efficiency realms they'll end up using a lot of dissimilar metal parts , thus necessitating fresh water cooling .

joseph m. hahnl
04-13-2015, 07:39 PM
The idea that not every boat is going to run in salt water has crossed my mind a few times before . The problem is that only 3% of all the water on earth is fresh water .

Just as a reference , when we ordered the 502Mag for the Mag 25 we already knew we wanted the FWC option and the supplier thought it was an excellent idea although he never mentioned anything about an aluminum intake .
It was probably more to do with the fact that he knew we were going to take care of it , especially considering that we're in some seriously salty water over here .

When I ordered the Volvo 5.7Gi for the St T I wanted FWC but I didn't think it was going to fit in the very limited space under the engine box . The supplier said that he ordered all of his engines with FWC whether the customer specified it or not.
I think I can recall him saying something about the aluminum intake manifold that Volvo used as being a big part of the reason.
Incidentally , it is mentioned in the voluminous Volvo owner's manual that they use a special alloy manifold of their design on that engine , but there's no mention of such a critter in the 502 handbook.

Otherwise, I think you're right George, and Matty , as the engines continue to evolve into ever more high performance and efficiency realms they'll end up using a lot of dissimilar metal parts , thus necessitating fresh water cooling . It seems like 95% of runabouts run on that mere 3% :biggrin.:

Morgan's Cloud
04-14-2015, 07:11 AM
It seems like 95% of runabouts run on that mere 3% :biggrin.:

It seems like you might need to travel a bit more :biggrin.: :biggrin.:

MOP
04-14-2015, 07:21 PM
The water passages in the aluminum manifolds are brass lined, they were machined afterwards slightest nick or edge exposure it blows off real fast.

Added note engines run much better at higher temps, I have never understood why so many don't run 180 Tstats. I ran a 180 for many years with -0- issues!

yeller
04-15-2015, 10:37 PM
Can anyone explain why a manufacturer of marine engines would use dissimilar metals in its construction , aluminum nonetheless , and NOT sell it as FWC only from the factory ?

(I've wondered this for a long time )I used the same aluminum intake and exhaust on my 16 for 18yrs and most of the boating was in brackish water with probably 30% of the time in salt. I flushed after every use and there was absolutely no signs of corrosion. I don't think aluminum is the problem. It's the maintanence. Don't flush it after use and it will corrode.

Morgan's Cloud
04-16-2015, 07:23 AM
I used the same aluminum intake and exhaust on my 16 for 18yrs and most of the boating was in brackish water with probably 30% of the time in salt. I flushed after every use and there was absolutely no signs of corrosion. I don't think aluminum is the problem. It's the maintanence. Don't flush it after use and it will corrode.

Certainly all 'fresh water ' isn't created equal , and it's amazing to read of some of the issues that some have experienced on different bodies of 'fresh' water.

I would expect that a large % of boats that are trailered to lakes and ponds are probably flushed out after use but at the root of my original remark was that the lion's share of all boats are not only in salt water but they stay over without haulout for all season or longer without flushing capabilities.

Tidbart
04-20-2015, 08:04 PM
I used the same aluminum intake and exhaust on my 16 for 18yrs and most of the boating was in brackish water with probably 30% of the time in salt. I flushed after every use and there was absolutely no signs of corrosion. I don't think aluminum is the problem. It's the maintanence. Don't flush it after use and it will corrode.

Just to elaborate, Yeller, you are correct, the problem is the maintenance, or lack thereof. The salt got to my intake due to the fact that the previous owner never flushed it. He kept it in stack storage for 5 years and I doubt it was ever flushed, to my detriment. With that said, the intake will last a long time with the correct care. It will last a lot longer with closed cooling.:yes:

Bob

smokediver
04-27-2015, 08:56 AM
I received and installed a Monitor closed cooling kit , block only. I decided to not pull the intake as there was no corrosion in the tstat housing and the area within the intake. I don't think monitor makes a distinction of wether or not it is a mag motor or not like other companies do. I had to pull my upper intake plenum to remove the brass fitting hidden underneath. It runs from the intake to port side pcv on the valve cover. The new water inlet with hose attached , made clearance an issue. I removed the fitting and ground it down , smoothed the edges , and was able to re install. Per the instructions I am using distilled water for coolant as the engine has seen salt water. I think it takes close to 5 gallons. After a month of running the boat and draining out the old water and adding new , I will add coolant.