Max runout?

Discussion in 'Engine, Fuel and Exhaust' started by leedham, Aug 25, 2010.

  1. leedham

    leedham Member

    66
    0
    0
    Hey guys!

    Here's a good one. If I decide to do gear drive cams on my '02 RK, what is the maximum allowable Total Indicator Reading on the crank runout to have a successful outcome ? All I'm reading are terms such as, "minor crank runout problems lead to....etc.
    Thanks !!!
     
  2. Hoople

    Hoople Account Removed

    7,198
    0
    34
    Depends where you measure it. At the ground surface of the cam plate bearing it needs to be .0015" or less. That's is if you want it to be right.
     
  3. R.Bingham

    R.Bingham Active Member

    317
    0
    4
    Max run out for gear drive is .003. You need to add together both measurements if the needle swings both ways for total run out.
     
  4. leedham

    leedham Member

    66
    0
    0
    O.K. I'm in agreement with .003". ( I just found that same number from Andrews website) Thanks for responding !!
     
  5. Hoople

    Hoople Account Removed

    7,198
    0
    34
    Now think about this for a second. How many cams would a cam manufacture sell if they told you a tight spec. These days it would be next to none. You know (or at least I do) deep down inside they want to say MUCH less but can't because they want to sell cams.

    Harley THEMSELVES say it should be .002" or less with their very own gear drive cams like which is found on their 1997-1998 engines.. It says so right in the service manual.

    The people to talk to is Not the people who sell cams. It's the machine shop engine builders.

    Since your pre- '07 you probably don't have too much to worry about and you just may see a really tight spec.

    But either way, please let us know how it works out...
     
  6. BUBBIE

    BUBBIE Well-Known Member

    4,959
    83
    113
    I AGREE! Like HOOPLE says.000.0015 :newsmile037:

    But if one way is .003 that would be .006 and way out...
    I had No Problems when going Gear on my 2000 FXDS.... The main thing was I was out under .0015 and It worked great.... Proper measuring of the gears (micrometer/round stock) turned out a perfect job!
    The older TC cranks were in tolerance More than the New bikes of today..

    signed....BUBBIE
     
  7. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

    4,633
    83
    101
    Just the facts, Ma'am, just the facts!:

    From TT324 – August 22, 2007 - Twin Cam Crankshaft Inspection & Run-Out Specifications

    Flywheel Specifications:
    Run-Out(crankshaft in the crankcase) 0.0 – 0.010 IN. 0.0 – 0.254 MM
    Run-Out (crankshaft on a truing stand) 0.0 – 0.004 IN. 0.0 – 0.102 MM

    Flywheel Service Wear Limits:
    Run-Out(crankshaft in the crankcase) 0.012 IN. 0.305 MM
    Run-Out (crankshaft on a truing stand) 0.005 IN. 0.127 MM

    Crankshaft Runout Inspection - Harley Davidson Community

    TQ
     
  8. Hoople

    Hoople Account Removed

    7,198
    0
    34
    TQ, Those are tolerances for the chain driven cams. Look back in a service manual that was gear driven. Whole different amount.
     
  9. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

    4,633
    83
    101
    Right. But HD is not gonna do anything for anyone with a crank runout under .012". Of course his '02 is probably out of warranty, so it may be on his nickel anyway.

    Andrews does indicate that the MAX runout for the gear-drive option is .003". But the target if someone is gonna have the crank trued, TIG welded and retrued should be in the .001" or less. Given spending that much time, effort and money to get the crank right, it would be a shame to aim at the max tolerance of the gear-drive option spec.

    TQ
     
    Last edited: Mar 7, 2011
  10. Hoople

    Hoople Account Removed

    7,198
    0
    34
    Oh I see what your saying now. I thought you were saying it would be OK to have something like .008" because that is what HD says is ok in the shop manual.

    I agree with what you said.
    I could not believe my eyes when I saw how beefy the early model cranks looked. I was reading a 1998 Softail manual the other day and the cranks look like they could survive a nuclear war.
    I don't know about the rest of the engine but the cranks you could put on display. They were beautiful.