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    #46
    Would this be an acceptable marine head gasket

    https://www.summitracing.com/search/...eyword=M110628

    If so this would give a q/e of .040 and s/c ratio of 8.98 to 1 with 72cc heads and 9.44 to one with 67 cc heads

    Any suggestions?
    1987 bayliner 2550 5.7 omc cobra i/o

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      #47
      Would a q/e of .051 be too much?
      1987 bayliner 2550 5.7 omc cobra i/o

      Comment


        #48
        .038 is the target number for the squish, may be doing this myself real soon😳
        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


          #49
          I was just wondering if .051 q/e is doable with good compression of 9.3 to 1 or if I can do 9.44 to 1 at .40 q/e
          1987 bayliner 2550 5.7 omc cobra i/o

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            #50
            If I had to choose between the two I’d go 9.44 with the .040
            my 2 cents
            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


              #51
              ..............
              Originally posted by 6549vincent View Post
              Would this be an acceptable marine head gasket

              https://www.summitracing.com/search/...eyword=M110628

              If so this would give a q/e of .040 and s/c ratio of 8.98 to 1 with 72cc heads and 9.44 to one with 67 cc heads?

              Since I'm not there with "hands on", I am not willing to do the math for you. There is just too much responsibility given the limited and changing info.

              Taking .012" off the deck reduces the OEM deck height from 9.025" to 9.013".
              Once a rod/piston assembly is installed, the piston deck height can be verified.
              Only then would the head gaskets be selected.

              Just curious..... are you able to post photos of the 72cc combustion chambers and the 67cc combustion chambers?
              Are both similar to this?






              I was just wondering if .051 q/e is doable with good compression of 9.3 to 1 or if I can do 9.44 to 1 at .40 q/e
              Would a q/e of .051 be too much?

              My take would be NO!
              Experts like Dennis Moore suggest a .038" quench or squish dimension for the Marine 5.7L SBC.
              The High Performance Automotive experts would suggest a greater quench or squish dimension (.050" to .060" ) due to the higher RPM.

              Rick E. Gresham, Oregon
              2850 Bounty Sedan Flybridge model
              Twin 280 HP 5.7's w/ Closed Cooling
              Volvo Penta DuoProp Drives
              Kohler 4 CZ Gen Set

              Comment


                #52
                A pic of summit's iron cast head
                Attached Files
                1987 bayliner 2550 5.7 omc cobra i/o

                Comment

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