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Closed Cooling? Which one to buy?

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  • Closed Cooling? Which one to buy?

    I’m trying to figure out which closed cooling system to go with. I have narrowed it down to Orca sold by Hardin/CP Perf or Monitor sold by Perf Protech. There is a significant price difference between the two; Orca is going for about $1600 each. The Monitor system through performance Protech is $1150 each.

    This is going on a Formula 280 with twin 350 mag mpi.

    will need 2 to complete the project so looking at a $900 difference for the 2 kits needed.

    Anybody have any experience with either set? Open to commentary or suggestions for other brands as well.

  • #2
    Ayuh,..... How old are the motors, 'n have they ever seen saltwater,..??


    • #3
      if the motors have ever seen salt water for more than simply a day or two, dont bother, you cant clean the inside of the block and heads enough to justify adding a HX

      if the motors are fresh-water only motors, highly suggested to pull the motors to clean out the blocks cooling water jacket enough prior to installing the HX's. no way to get enough of a flush without removing the heads, flipping upside down and manually cleaning the block

      Monitor was one of the early suppliers to Mercruiser. however Alfa Laval (Champ Products) has been the supplier of choice for the past 15 years.
      Cheesehead boating the Gulf Coast of FLA 27.51° N, 82.53° W

      1988 Cruisers Rogue 2420 -VP 290 DP now powered by custom 468 - https://forums.iboats.com/forum/owner...988-rogue-2420

      Past Boats
      1970 Wooster Hellion - Merc 9.8
      2002 SeaRay 190BR - 5.0 - A1G2 - "Cheeseheads in Paradise"
      1984 Avanti 170DLI -3.0 stringer- "Ship Happens"

      What’s behind you doesn’t matter.Enzo Ferrari


      • #4
        Never seen salt water.


        • #5
          Originally posted by blamtro View Post
          Never seen salt water.
          Ayuh,..... Even a freshwater motor is gonna have rust scale in the coolin' passages, which will plug up the uncleanable side of the exchanger,.....

          For that reason, freshwater coolin' systems are only added to virgin motors, either brand new, or freshly reman motors,....


          • #6
            I've installed plenty of the monitor kits. They work fine. With most any aftermarket kit you will have to read directions and trim hoses. I do appreciate that they include mercury elbow gaskets and not the junk green sierra style ones. One thing to check for is flatness of the thermostat housing. I've had two leak in the past where I then had to go back in and disconnect hoses i just put on, remove the heat exchanger i just mounted to get to the housing which needed to be re- decked.

            Mercury claims they cant run a full closed system on a SB with an Alpha drive. Monitor has a kit that can. Reason we put on quite a few.


            • #7
              Also I'll agree with the others on not putting a FWC kit on a used engine. It will clog or rot out the heat exchanger pretty much guaranteed.


              • #8
                Im going to bite the bullet and do a good flush and add this inline filter in before the heat exchanger. I believe tpenfield did it too without any ill effects.


                • #9
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                  Originally posted by blamtro View Post
                  Im going to bite the bullet and do a good flush and add this inline filter in before the heat exchanger. I believe tpenfield did it too without any ill effects.

                  I added closed cooling kits (from San Juan Engineering) to my twin 7.4 MPI engines. They had only seen fresh water and I was going to run them in the salt. I think the kits were about $1,000 each.

                  A couple things that I would recommend . . .

                  Get the Full systems, not the half system. No need to be replacing exhaust manifolds every few years.

                  Do a high volume flush of the engine block to get any sand/mud out of the block. Then . . . Do a soak & flush of the the engine's current cooling system with an oxalic acid (wood bleach) solution, then neutralize it with a baking soda solution before you add the closed cooling. This should get the rust sediment out of the engines.

                  Replace the manifold/riser/elbow gaskets so you have a good seal there.

                  Post some pictures as you go . . .
                  Best regards, Ted . . . . Cape Cod, MA

                  Current Boats: Formula 330 Sun Sport, O'Day Mariner Sail #3224, Sunfish
                  Past Boats: Catalina 22 Sail #10531, Formula 242 Sun Sport
                  Twin Mercruiser 7.4 LX MPI (0F802036, 039), Bravo 3's (0F806198, 199), Mercury 7.5 HP (1969), Johnson 4.5 HP (1980)

                  My Boating Web Pages: http://www.tpenfield.com