Elgin Outboard Impeller swap

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  • November 23, 2022 at 5:20 pm #269302
    Buccaneer
    Participant

      US Member

      Just wanted to show a seemingly successful Elgin impeller
      swap, replacing the original 10 vane rubber impellers (one inch plus tall)
      with two Mercury impellers stacked together.
      Slight modifications were required, such as drilling the driveshaft
      for two impeller drive pins, to drive the Merc impellers.
      The original Elgin impeller was driven by the driveshaft splines.
      The driveshaft is “very” hard drilling by the way!
      Thanks to Brian Wilcox for “tips” on doing this conversion!

      My camera was aimed a little “low”, but it appears to be pumping water
      plenty good. How it will hold up will be the real test.

      https://youtu.be/Do6N6ho9gaY

      Prepare to be boarded!

      November 23, 2022 at 7:10 pm #269309
      Al
      Participant

        US Member

        buccaneer

        can you share the part number for the mercury impeller your using in the elgin outboard thanks AL

        November 23, 2022 at 8:07 pm #269310
        seakaye12
        Participant

          US Member

          Some of those driveshafts are hardened steel.  Was it difficult to drill?

          November 23, 2022 at 9:04 pm #269311
          bobw
          Participant

            US Member

            Buc – looks like it works great.   Glad it worked out!

            Bob

            1937 Champion D2C Deluxe Lite Twin
            1954 Johnson CD-11
            1957 Evinrude Fastwin 18
            1958 Johnson QD-19
            1958 Johnson FD-12
            1959 Johnson QD-20

            “Every 20 minute job is only a broken bolt away from a 3-day project.”
            "Every time you remove a broken or seized bolt an angel gets his wings."

            November 23, 2022 at 10:16 pm #269313
            Buccaneer
            Participant

              US Member
              Al wrote:

              buccaneer

              can you share the part number for the mercury impeller your using in the elgin outboard thanks AL

              I used Mercury 47-89981 impellers.
              Sierra 18-3039

              They’re a little loose on the driveshaft, but I fit the
              drive pins tight to compensate.

              Prepare to be boarded!

              November 23, 2022 at 10:20 pm #269314
              Buccaneer
              Participant

                US Member
                seakaye12 wrote:

                Some of those driveshafts are hardened steel.  Was it difficult to drill?

                I spot drilled them with a machinist “center drill” on the milling machine,
                the switched to the size drill bit I wanted. I managed to drill the first
                hole to depth, about .200, but the drill wouldn’t touch the other
                hole, nor the other four bits I tried, lol.
                I ended up using the center drill to go to depth, which worked okay,
                but I had to use a larger diameter pin than I intended, which
                may have been better anyway.

                Prepare to be boarded!

                November 24, 2022 at 6:44 am #269315
                billw
                Participant

                  US Member

                  You had mentioned that you also had ordered the Sierra equivalent of 47-89980. Did you end up feeling that they were too tight on the shaft?

                  Long live American manufacturing!

                  November 24, 2022 at 9:17 am #269316
                  Buccaneer
                  Participant

                    US Member
                    billw wrote:

                    You had mentioned that you also had ordered the Sierra equivalent of 47-89980. Did you end up feeling that they were too tight on the shaft?

                    Those ended up being “bigger”.
                    The 47-89981 I used had a center bore of .453
                    and the 47-89980 were .457.

                    Someone mentioned they had to bore the hubs ever so slightly
                    to fit over the driveshaft. Not sure what make or number those
                    impellers would have been.

                    All the impellers I got were Chinesium, so “fit” may not be as
                    good as the OEM impellers.
                    When I ordered the impellers, I ordered six all together, not
                    being sure if I was fixing two motors or one, or which impellers
                    would work out.

                    Prepare to be boarded!

                    November 24, 2022 at 9:32 am #269317
                    The Boat House
                    Participant



                      Including the pictures you posted in projects
                      might be helpful for others needing a substitute
                      for their Elgin.
                      Tubs                      .

                      November 24, 2022 at 5:27 pm #269340
                      Buccaneer
                      Participant

                        US Member
                        The Boat House wrote:



                        Including the pictures you posted in projects
                        might be helpful for others needing a substitute
                        for their Elgin.
                        Tubs                        .

                        Thanks for mentioning that Tubs.

                        Photos, including the impellers swap, in Current Projects…….
                        https://www.aomci.org/forums/topic/1951-elgin-7-5-hp/

                        Prepare to be boarded!

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