1938 DT-38 Johnson 4.2 hp crankcase

Home › Forum › Ask A Member › 1938 DT-38 Johnson 4.2 hp crankcase

Viewing 5 posts - 1 through 5 (of 5 total)
  • Author
    Posts
  • September 13, 2017 at 1:33 am #8216
    Buccaneer
    Participant

      US Member

      I tore apart the crankcase on the subject motor.
      There’s an oil drain galley / passage between
      the upper and lower crankshaft main bearings.
      Inside the galley is a tiny copper tubing, shaped
      to fit inside of the galley.
      Is this suppose to be there, or is it something someone
      added? If someone decided it needed a restriction,
      why not just have a short piece in the middle?
      Thanks!

      Attachments:

      Prepare to be boarded!

      September 14, 2017 at 12:11 am #64853
      Buccaneer
      Participant

        US Member

        I could not find anything in the 3rd Edition Johnson service manual about
        the little tube in the oil drain galley, and never have come up with
        a parts manual for this era of 1938 to 1940 4.2 and 5 hp Johnsons.
        I did find a "froze up" parts engine on the rack, so I tore that apart today.
        That too, had the little copper tube in the oil drain galley….. strange design..
        or poor engineering?

        Prepare to be boarded!

        April 22, 2020 at 7:51 am #200773
        HayFever
        Participant

          Hey Mr. Buccaneer —- I too have found the same thing in my LT37 — serial 33072 — made in Peterboro , Canada — I too found it peculiar???? And as with you — wondered why??? On the opposite cover is residue of the same gallery — making me realize there was no gasket between and flow did occur on the outside of the ‘tube” ??? Flow speed restrictor — along full side of cover ??? to evenly distribute cooling — a piece in the middle would cause a cool and hot side ???

          John

          April 22, 2020 at 8:42 am #200775
          Buccaneer
          Participant

            US Member

            Well at least now I know that the tube was suppose to be there, lol.

            Prepare to be boarded!

            April 22, 2020 at 8:58 am #200778
            dave-bernard
            Participant

              US Member

              I would say to keep sealer out of the galley. just a thought.

            • Author
              Posts
            Viewing 5 posts - 1 through 5 (of 5 total)
            • You must be logged in to reply to this topic.