factory bore specs for a 1957 18 Johnson?

Home › Forum › Ask A Member › factory bore specs for a 1957 18 Johnson?

Viewing 4 posts - 1 through 4 (of 4 total)
  • Author
    Posts
  • November 22, 2021 at 5:31 am #250031
    billw
    Participant

      US Member - 2 Years

      I am finally getting back to looking into having my FD block bored .020″ oversize. Does anybody have factory the bore spec for this engine? Obviously, we would add .020″ to that spec! I remember hearing once that, unlike automotive, you shouldn’t just hand the piston over to a machinist an have him bore it according to the piston, because the running clearances are different than automotive. All thoughts welcome.

      Long live American manufacturing!

      November 22, 2021 at 8:16 am #250033
      frankr
      Participant

        US Member - 1 Year (includes $3 online payment fee)

        Piston to cylinder clearance 0.003″ min, 0.0045″ max, AT THE SKIRT (they are tapered).

        November 22, 2021 at 9:33 pm #250076
        johnny
        Participant

          US Member - 1 Year (includes $3 online payment fee)

          Factory Bore is 2-1/2″.

          November 23, 2021 at 5:44 am #250079
          billw
          Participant

            US Member - 2 Years

            Thanks, both of you. Good info. I appreciate it.

            Long live American manufacturing!

          • Author
            Posts
          Viewing 4 posts - 1 through 4 (of 4 total)
          • You must be logged in to reply to this topic.