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Re: Flywheel assembly: pressing/pulling apart?

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  • Tristan Edwards
    thanks dvm, is nearside the driveside and offside the timing side? (lame question but i honestly dont know those terms!) I will go into the mechanics next week
    Message 1 of 8 , Jul 1, 2006
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      thanks dvm, is nearside the driveside and offside the timing side?
      (lame question but i honestly dont know those terms!)

      I will go into the mechanics next week and press it out with him.

      --- In royalenfield@yahoogroups.com, "glssgrg" <glssgrg@...> wrote:
      >
      > Ooops, I done mis-spoke.
      > The nearside driveshaft has no nut, just a key and a machined
      shoulder.
      > The offside timing shaft is keyed and nutted between the flywheels.
      > As I said, usually no need to take them apart.
      >
      >
      >
      > --- In royalenfield@yahoogroups.com, "glssgrg" <glssgrg@> wrote:
      > >
      > > You have a good mechanic, there. He stopped BEFORE breaking
      something.
      > > The crankpin has no threads other than the external hex nuts,
      press fit only. I was able
      > to
      > > knock them apart with a good size hammer and a big brass drift.
      It was tight. It should
      > > press out. (If brute force ain't workin', ya ain't usin' enough.)
      > > On reassembly, you have to be REAL careful to get the oilways in
      the offside flywheel
      > and
      > > the crankpin lined up. It may be best to remove the nearside
      wheel only.
      > > The center shafts are keyed and pressed, but have no external hex
      nuts. No reason to
      > take
      > > them apart unless damaged.
      > > Best,
      > > DWM
      > >
      > >
      > > --- In royalenfield@yahoogroups.com, "Tristan Edwards" <t_w_e@>
      wrote:
      > > >
      > > > Hi all,
      > > >
      > > > I've recieved my parts from England for my engine rebuild
      (gaskets,
      > > > new bigend bush), and my flywheel assembly is now at a trusted
      local
      > > > mechanic to be pressed apart.
      > > >
      > > > The mechanic has made one attempt so far to press the flywheels
      apart
      > > > but has given me a phonecall asking if i am POSSITIVE that it
      IS a
      > > > question of pressing(not some sort of screw). He said that
      while
      > > > trying to press apart it showed no signs of movement so he
      stopped
      > > > before the possibility of damaging the assembly (thus his
      > > > questioning).
      > > >
      > > > Does anyone have any experience with these flywheel
      assemblies? Do
      > > > they just require HUGE force to be pulled apart? The mechanic
      said
      > > > that once i am possitive that it only required a press action
      then he
      > > > will apply more force. He's got a 20 tonne press so he should
      be
      > > > able to do it then.
      > > >
      > > > Thanks and any help appreciated.
      > > >
      > > > -Tristan
      > > >
      > >
      >
    • glssgrg
      Sorry bout that. My Dad always used the terms regarding bikes, he was a Brit (Ulster Scot, actually.) Nearside and offside go back to horses, the nearside
      Message 2 of 8 , Jul 1, 2006
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        Sorry 'bout that. My Dad always used the terms regarding bikes, he was a Brit (Ulster Scot,
        actually.)
        Nearside and offside go back to horses, the nearside (left) is the side you get on, offside
        (right) is the side you fall off.

        I'd like to hear more, from the people who have done it, regarding crankshaft assembly
        and trueing. I've done Harley cranks, but they are easier, being tapered shafts. The books
        speak of checking flywheel runout on a lathe (I just got one!), but don't much go into how
        to get rid of any irregularity. The two flywheels should be as perfectly superimposed on
        each other as possible, or the crank will wobble. Problem is, the press fit on the crankpin
        ends is so tight, I don't know how one would move one flywheel relative to the other.
        My plan;
        -Prove the oilway path from the timing shaft into the right flywheel, adjust if neccessary.
        -Measure up the oilway location in the crankpin and in the flywheel, mark both accurately,
        then press the crankpin into that flywheel. Prove oilway again.
        -----(Personal Bias; I plugged the pressure relief valve, the timing shafts didn't have them
        for years, and I can see no reason whatever to divert oil pressure and flow from the big
        end, which is where I want ALL the oil to go.)
        - Find a real flat piece of Formica countertop, drill a hole for the timing shaft, then set the
        right flywheel down on it with the shaft through the hole. Drop on the new Big End
        bushing AND THRUST WASHERS.
        -Place the left flywheel, with the driveside shaft installed, on the crankpin, just tap it with
        a brass hammer to "start" it, then go around the flywheels with a machinist's square set on
        the flat surface to get the flywheel circumferences as close to exactly the same as
        possible. Tap a bit, recheck, until the flywheel stays in place.
        -Take it to the press, press in about 1/4"-3/8". Take back to flat surface and recheck, The
        flywheels should still turn relative to each other with a brass or lead hammer, fairly easily,
        as so little of the crankpin is pressed into the flywheel.
        -Press again, to 1/2 " or so, check again. The further the crankpin is pressed in, the
        harder it should be to align the flywheels, the idea is to have good alignment before it gets
        too hard to turn. When it starts to get close, and if you have a lathe,
        (I NOW HAVE ONE!) (The Enfield crankshaft fits between centers.)
        http://www.cumminstools.com/browse.cfm/4,876.htm
        and check runout with a dial indicator.
        -At some point, the flywheels should begin to maintain alignment between pressings, at
        which timet, one can simply press in all the way.
        Comments?
        DWM
        BTW, Haven't heard much from Horst and his Rennfield lately. I've heard they're playing
        some kind of Metric Football over there.


        --- In royalenfield@yahoogroups.com, "Tristan Edwards" <t_w_e@...> wrote:
        >
        > thanks dvm, is nearside the driveside and offside the timing side?
        > (lame question but i honestly dont know those terms!)
        >
        > I will go into the mechanics next week and press it out with him.
        >
        > --- In royalenfield@yahoogroups.com, "glssgrg" <glssgrg@> wrote:
        > >
      • Pete Snidal
        ... Great question! I ve been reading those terms for over 50 years, and I still can t get it right! They re Brit-speak and refer to which side is closest to
        Message 3 of 8 , Jul 1, 2006
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          >thanks dvm, is nearside the driveside and offside the timing side?
          >(lame question but i honestly dont know those terms!)

          Great question! I've been reading those terms for over 50 years, and
          I still can't get it right! They're Brit-speak and refer to which
          side is closest to the "kerb," I think. But just when I figure out
          what it's near to, then I get screwed up with whether it's the kerb
          or the curb (the latter being on the right, the former on the left.)
          So, in the interests of clarity, let me suggest this:

          "Leave the shaft with the hole in the middle in its flywheel if
          at all possible."

          If it's only big-end work, you can leave them both alone. If it
          works,.... DFI!
        • Pete Snidal
          ... Every positive-displacement pump hydraulic system HAS to have some means of pressure relief above a certain limit. It would appear that the Indian models
          Message 4 of 8 , Jul 2, 2006
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            >-----(Personal Bias; I plugged the pressure relief valve, the timing
            >shafts didn't have them
            >for years, and I can see no reason whatever to divert oil pressure
            >and flow from the big
            >end, which is where I want ALL the oil to go.)

            Every positive-displacement pump hydraulic system HAS to have some
            means of pressure relief above a certain limit. It would appear that
            the Indian models depended on the pump discs unseating themselves
            against the springs at the high pressure cutoff. Seems to me that the
            ball/spring arrangement - used by pretty well every other machine
            _I'_ve ever had apart, would be more consistent and reliable - and
            maybe run MORE oil through the bigend.

            >- Find a real flat piece of Formica countertop, drill a hole for the
            >timing shaft, then set the
            >right flywheel down on it with the shaft through the hole. Drop on
            >the new Big End
            >bushing AND THRUST WASHERS.
            >-Place the left flywheel, with the driveside shaft installed, on the
            >crankpin, just tap it with
            >a brass hammer to "start" it, then go around the flywheels with a
            >machinist's square set on
            >the flat surface to get the flywheel circumferences as close to
            >exactly the same as
            >possible. Tap a bit, recheck, until the flywheel stays in place.

            A "V-Block" is the standard machinist's tool at this point - possibly
            a clean piece of 3 or 4 inch angle iron, arranged point down (welded
            feet?) would get things into fairly decent alignment here.

            >-Take it to the press, press in about 1/4"-3/8". Take back to flat
            >surface and recheck,

            This is where I'd chuck the timing-side crankpin in the lathe and do
            a runout check with dial gauge. -
            radial and axial. Get it right with the hammer and then carefully
            press it on more, repeat to taste.

            >The
            >flywheels should still turn relative to each other with a brass or
            >lead hammer, fairly easily,
            >as so little of the crankpin is pressed into the flywheel.

            10-4!

            >-Press again, to 1/2 " or so, check again. The further the crankpin
            >is pressed in, the
            >harder it should be to align the flywheels, the idea is to have good
            >alignment before it gets
            >too hard to turn. When it starts to get close, and if you have a lathe,
            > (I NOW HAVE ONE!) (The Enfield crankshaft fits between centers.)

            We agree, with the difference that I'd do the lathe check earlier,
            and do it with the timing-side pin chucked in the headstock. That
            between-centers stuff is just for the poor people who don't have a
            real lathe....

            >http://www.cumminstools.com/browse.cfm/4,876.htm
            >and check runout with a dial indicator.
            >-At some point, the flywheels should begin to maintain alignment
            >between pressings, at
            >which timet, one can simply press in all the way.
            >Comments?
            >DWM
            >BTW, Haven't heard much from Horst and his Rennfield lately. I've
            >heard they're playing
            >some kind of Metric Football over there.

            I think you mean Girl's Rugby! Rugby is the Real Mans game with no
            padding and no substitutes.
            You're either on the field or on a stretcher! 2 30-min periods, no
            commercial breaks.
          • glssgrg
            ... When I installed the new big-end, I injected oil into the timing shaft with a child s drug dosage syringe, and was amazed at the very low pressure that
            Message 5 of 8 , Jul 2, 2006
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              --- In royalenfield@yahoogroups.com, Pete Snidal <snidey@...> wrote:
              >
              > Every positive-displacement pump hydraulic system HAS to have some
              > means of pressure relief above a certain limit. It would appear that
              > the Indian models depended on the pump discs unseating themselves
              > against the springs at the high pressure cutoff. >

              When I installed the new big-end, I injected oil into the timing shaft with a child's drug
              dosage syringe, and was amazed at the very low pressure that opened the relief valve.
              Once you get fifty miles or so on the new big-end, it's not a closed system, and I'd prefer
              to valve off pressure there. Finally, a bit of drek in the relief causes it to "Fail-Dangerous",
              and I want as few eventualities as possible resulting in reduced oil pressure to the big-
              end.
              In any case, a really high pressure peak would probably just bypass the oil feed seal, and
              dump into the timing case.

              >
              > A "V-Block" is the standard machinist's tool at this point - possibly
              > a clean piece of 3 or 4 inch angle iron, arranged point down (welded
              > feet?) would get things into fairly decent alignment here.

              The nice thing about the formica, other than its availability, is that you can go around the
              flywheels with the square without moving them, but a real machinist's V-block would be
              nice, too.
              >
              > We agree, with the difference that I'd do the lathe check earlier,
              > and do it with the timing-side pin chucked in the headstock. That
              > between-centers stuff is just for the poor people who don't have a

              Good point there, no point in having a nice 3 jaw chuck and not flaunting it.
              (Did I mention I now have one?)

              > >BTW, Haven't heard much from Horst and his Rennfield lately. I've
              > >heard they're playing
              > >some kind of Metric Football over there.
              >
              > I think you mean Girl's Rugby! Rugby is the Real Mans game with no
              > padding and no substitutes.
              > You're either on the field or on a stretcher! 2 30-min periods, no
              > commercial breaks.

              Rugby is the best of the lot, I suppose, but Rugby, Metric Football, and 'Murkin Football all
              only require one ball.
              Unlike motorcycling.

              Best,
              DWM
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