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    Exhaust Corrosion

    So as a boating newbie I recently purchased a 2012 Bayliner 195 which had a major oil leak resulting in a seized engine. Engine was rebuilt and overhauled. When the exhaust was removed I noticed it had a lot of corrosion. The mechanic said the exhaust is ok and doesn't need replacing and since the overhaul the engine has worked smoothly.

    I just had a look at the pictures from when the engine was removed prior to being overhauled and the exhausts didn't look pretty.

    Any thoughts on if I should take the mechanics word that the exhausts are ok? Having read about hydrolocked engines I am paranoid to say the least.

    Thanks

    #2
    I would NEVER put old exhaust on a new engine. Unless maybe I knew they had maybe one season on them. Just me.
    1989 Avanti 3450 Sunbridge
    twin 454's
    MV Mar-Y-Sol
    1979 Bayliner Conquest 3150 hardtop ocean express.
    Twin chevy 350's inboard
    Ben- Jamin
    spokane Washington

    Comment


      #3
      You have the newer dry joint exhaust system mounted. It’s hard to tell from your pic (and I’m a little confused by the plumbing at the bottom of the manifold) but it may be a full closed system. If so your manifolds and spacers could last a long time. The exhaust elbows will require some attention. It’ll be much better than the older raw water cooled wet joint style. The only real way to tell is to pull the exhaust to examine.
      Dave
      Edmonds, WA
      "THE FIX"
      '93 2556 5.7 Bravo II 2.0:1 18 1/4x19 P
      (.030 over-Vortec top end-part closed cooled)
      The rebuild of my 2556 https://www.baylinerownersclub.org/f...76?view=thread
      Misc. projects thread
      https://www.baylinerownersclub.org/f...56-gctid789773

      Comment


        #4
        As Dave said you have the dryjoint system which reduces the opportunity of water entering the engine due to a leaky joint. The plumbing doesn’t look like clos3d cooling to me but instead Mercruiser’s single point drain system. It does look like the gaskets between the manifold/riser/elbow are/were leaking. Ask the shop if they replaced them. The output of the elbow looks open and clear, three openings at top. But without inperson inspection I cannot say more than that.
        1997 Maxum 2400 SCR 5.7LX Bravo II

        Mike

        Comment


        • builderdude
          builderdude commented
          Editing a comment
          Ah, single point drain system. See I’m not up to speed. What about the hose connected to the exhaust elbow? Or am I seeing things?

        • Nauti_Mike
          Nauti_Mike commented
          Editing a comment
          Not sure Dave I see something but I may be the wiring harness or a hose, picture of that area is required.

        #5
        They don't look too bad but I do see flaking rust on the outlet. I'd go by what you know of the previous use...if it was a salt water boat and you don't know if the elbows were ever changed, it might be a good idea to change them. The problem with exhaust rust is its not what you can see that worries you, its what you CAN'T see that worries you...as in internal corrosion.

        Here in salt water we usually look to change at least the elbows at 5-7 years, if not both the elbows and manifolds. I have filled old manifolds with acetone off the boat to check for leaks because acetone has lower surface tension than water and will find leaks that are not obvious until the cast iron heats up. Also you go by the condition of the sealing surfaces, if they are eroded enough to prevent the gaskets from sealing either you have to get the parts re-surfaced at a machine shop or replace them. Not at all worth the risk on a new engine.
        88 Four Winns 200 Horizon 4.3 OMC
        98 Jeep Grand Cherokee 4.0/Selectrac
        07 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

        Long Island Sound Region

        Comment


          #6
          Thank you for such informative responses. The gaskets were all changed and the sealing surfaces were intact. I guess the flaking at the tip of the exhaust was concerning me the most. The boat lives in saltwater in Qatar. I was hoping to sell the boat within 6 months and didn't want to have the expense of changing the exhausts unless it was absolutely necessary.

          Comment


            #7
            Don’t chance it. I just had to replace an engine because of a leaking cooling system. Hydro lock is not pretty.
            Glen Sherwood
            1987 3270 twin 305’s
            Coupeville, WA

            Comment


              #8

              nuwavemarine 625 American dollars complete kit and all the gaskets.Click image for larger version  Name:	shopping.png Views:	1 Size:	4.3 KB ID:	507099
              Be good, be happy, for tomorrow is promised to no man !

              1994 2452, 5.0l, Alpha gen. 2 drive. Sold ! Sold ! Sold !

              '86 / 19' Citation cuddy, Merc. 3.0L / 140 hp 86' , stringer drive. Sold ! Sold ! Sold !

              Manalapan N.J

              Comment


              • Nauti_Mike
                Nauti_Mike commented
                Editing a comment
                The OP has Dryjoint exhaust.

              • builderdude
                builderdude commented
                Editing a comment
                With spacers. The dryjoints cost substantially more, even the aftermarket stuff.

              #9
              True the dry joint is a better design but more expensive. I thought of switching to the Merc dry joint when I did the top end overhaul on my 4.3 but I knew the Volvo center riser exhaust would fit perfect so I went with those. Maybe if I keep it long enough for the next change 5 years from now lol.

              the OMC batwings I originally had became NLA years back but I bought a few sets when I could still get them. I never had leaks with those because they were all one piece.
              88 Four Winns 200 Horizon 4.3 OMC
              98 Jeep Grand Cherokee 4.0/Selectrac
              07 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

              Long Island Sound Region

              Comment


              • builderdude
                builderdude commented
                Editing a comment
                I’d love a set of hi-tech ss exhaust manifolds, all one piece but very pricey.

              #10
              You know I looked into those, and did a bit of research. I heard some good and some not so good, in that sometimes the welds failed or burned through causing leaks. They do look great though! If I ever re-powered this boat I'd try to go with a full closed system, that leaving only the elbows that need to be replaced on a 5-7 year schedule in salt water.
              88 Four Winns 200 Horizon 4.3 OMC
              98 Jeep Grand Cherokee 4.0/Selectrac
              07 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

              Long Island Sound Region

              Comment

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