Vespa-Ciao.NL
:: 46 mm Polini, no stamped arrow on piston??

Home Forums English General questions 46 mm Polini, no stamped arrow on piston??

5 berichten aan het bekijken - 1 tot 5 (van in totaal 5)
  • Gebruiker
    <i class="fa fa-comments-o" aria-hidden="true" style="font-size: 20px;"></i>
  • #144502

    Dea_944t
    Topic starter
    Berichten: 87

      Putting together a speed engine with 46 mm Polini kit but there is no “exhaust-arrow” on the piston…..
      The instructions are a bit confusing:

      “”if there isn’t any arrow fit the
      piston with the piston pin rings towards the induction””

      There is no such thing as a piston pin ring…. there are piston rings and there are piston pin lock rings

      Anyone that has a picture or a better explanation?

      /Dea

      #146853

      Edjuh
      Bijdrager
      Berichten: 6956

        There are obviously 2 ways you can fit the piston. Ideally, the piston ring ends should’nt run in transfer (or exhaust) ports, so check both ways of fitting to see which one is favorable.

        The 46mm polini piston has 2 holes that match the upper transfer ports and the 2 huge openings to match the main transfers. If you line those up you should be good.

        #146854

        Dea_944t
        Topic starter
        Berichten: 87

          The piston ring-ends does not run in any ports regardless which way the piston is put in.

          First I put it so that the two small holes in the piston matched the transfer ports in the cylinder, this way there is no holes in the piston matching the exhaust port, this is the way all other tuning cylinder pistons (like DR) are mounted. But then I read the instructions and looking both at the english and german instructions they seem to indicate that the piston ring ends should be towards the intake which is the other way around compared how I would like to mount it and then the confusion started….

          Here are some pics on how I think it should be mounted but then the ring ends will point towards the exhaust port and not the intake.

          #146855

          zevenenergie
          Donateur
          Berichten: 4167

            Your doing just fine,:thumb
            The end of the rings should face te exhaust port.

            #146856

            Dea_944t
            Topic starter
            Berichten: 87

              Thanks!

              Update: started and runs Ok 🙂

            5 berichten aan het bekijken - 1 tot 5 (van in totaal 5)
            • Je moet ingelogd zijn om een reactie op dit onderwerp te kunnen geven.