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  • Thermostat housing swap

    Can I keep my original hoses swapping over to a one piece Sierra 18-1989 t-stat housing from the original cast iron Merc housing 87290A4?

    Sierra

    http://www.boatersland.com/images/img/sie18-1989.jpg

    Merc

    http://www.boatpartheadquarters.com/...M-13230-2T.jpg
    1988 Imperial V220, 260/5.7 Alpha One
    https://forums.iboats.com/forum/boat...220-low-budget

  • #2
    Looks like I remove the hoses to the risers?
    1988 Imperial V220, 260/5.7 Alpha One
    https://forums.iboats.com/forum/boat...220-low-budget

    Comment


    • #3
      Originally posted by JaCrispy View Post
      Can I keep my original hoses swapping over to a one piece Sierra 18-1989 t-stat housing from the original cast iron Merc housing 87290A4?

      Sierra

      http://www.boatersland.com/images/img/sie18-1989.jpg

      Merc

      http://www.boatpartheadquarters.com/...M-13230-2T.jpg
      IMO no, you would need to replace the exhaust manifolds and elbows as well. Here is your design
      Click image for larger version

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      Here is the later design
      Click image for larger version

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      Last edited by AllDodge; January 23rd, 2015, 07:28 AM.
      94 Formula 27PC Custom 509MPI MEFI3 , B3 XR
      95 Rinker 232 w/ 7.4L Carb 0F425011 B1 0F486471
      07 Seadoo GTX
      Merc Adults Only VP Adults Only
      G-Dad always said "First Liar doesn't stand a chance"

      Comment


      • #4
        Manifolds? Why?

        The newer housing looks to not use water hoses to the risers. I'm thinking would just plug the risers.

        Old style

        http://www.boatdesign.net/forums/att...m-boat-002.jpg

        New style

        http://daddyosmarine.com/home/wp-con...d-Complete.jpg

        E
        dit: Looks like the housing in this pic

        http://i205.photobucket.com/albums/b...m/IMG_0009.jpg
        Last edited by JaCrispy; January 23rd, 2015, 07:40 AM.
        1988 Imperial V220, 260/5.7 Alpha One
        https://forums.iboats.com/forum/boat...220-low-budget

        Comment


        • #5
          Originally posted by JaCrispy View Post
          Manifolds? Why?

          The newer housing looks to not use water hoses to the risers. I'm thinking would just plug the risers.

          Old style

          http://www.boatdesign.net/forums/att...m-boat-002.jpg

          New style

          http://daddyosmarine.com/home/wp-con...d-Complete.jpg
          Then your correct you probably don't have to replace your exhaust, only the gaskets going between manifolds and elbows. Didn't know for sure since no serial number was given. To verify we would need your engine serial number. There can also be a water pump issue but like before would need serial number to determine.
          94 Formula 27PC Custom 509MPI MEFI3 , B3 XR
          95 Rinker 232 w/ 7.4L Carb 0F425011 B1 0F486471
          07 Seadoo GTX
          Merc Adults Only VP Adults Only
          G-Dad always said "First Liar doesn't stand a chance"

          Comment


          • #6
            Eng# 0B733876

            I just bought riser gaskets, 2 sides have large openings and 2 sides just have 2 small holes.
            1988 Imperial V220, 260/5.7 Alpha One
            https://forums.iboats.com/forum/boat...220-low-budget

            Comment


            • #7
              To properly do the conversion you also need to understand that you will be going from 'warm' manifolds to 'cold' manifolds. Once you understand that, and what that means, by all means go ahead and make the conversion. Just be sure you have 'full flow' gaskets between the manifolds and the elbows. And as long as each hose from the bottom of the manifolds reaches the correct port on the new thermostat housing, you can even reuse them, but if they don't you'll need to replace them too.

              Chris....
              xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
              The world takes on a whole new perspective when viewed from 100’ below.
              1972 Bertram ‘Bahia Mar’ 20
              2006 Mercruiser 4.3MPI (0W617679) w/Alpha One Gen II (0W829301)
              (Original - 1972 '165' In-line 6. Previous - 1994 4.3LX)


              Comment


              • #8
                Here is the service bulletin on stainless to cast iron elbows, you shouldn't need it unless your elbows are in bad shape
                http://www.mercruiserparts.com/bulle...1999/EN_01.PDF

                Appears it will work and you have the correct gasket (item 9 only two large holes)
                http://www.mercruiserparts.com/Show_...XH%2E+ELBOW%29

                The elbow hoses would be removed and the other hoses would go to the bottom of the manifold. Just did some looking and it should work, only issue that may appear is keeping the block full of water. The older designed used the thermostat to keep water restricted to the block until the thermostat opened. The check valves in the exhaust elbows also helped keep everything filled. The alpha drive does not supply the same amount of water that the belt driven pump does on a bravo. So the only possible issue I can see is maybe some heat issues. If this turns out to be the case (not saying it will) may need to look into other options.

                This pic is for illustration only, it's not yours but design issues are the similar

                Click image for larger version

Name:	898 cooling.jpg
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ID:	9253179
                94 Formula 27PC Custom 509MPI MEFI3 , B3 XR
                95 Rinker 232 w/ 7.4L Carb 0F425011 B1 0F486471
                07 Seadoo GTX
                Merc Adults Only VP Adults Only
                G-Dad always said "First Liar doesn't stand a chance"

                Comment


                • #9
                  Sign up today
                  Did some reading:

                  https://www.perfprotech.com/blog/tec...d-cooling-tips

                  https://www.perfprotech.com/blog/art...e-exhaust-tips


                  Looks like it will work but, like Chris said, I need to replace/cut out my elbow gaskets.
                  1988 Imperial V220, 260/5.7 Alpha One
                  https://forums.iboats.com/forum/boat...220-low-budget

                  Comment

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