crank runout

Discussion in 'Engine, Fuel and Exhaust' started by leedham, Feb 24, 2011.

  1. leedham

    leedham Member

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    Hey folks,

    As I'm putting together information before a gear cam install, the crank runout becomes the next question. I believe Andrews says to check the crank runout with the cam plate installed however, on the internet videos, there seems to be more crank runout checking done with the cam plate off. Which will give me the most accurate answer. As always, thanks !!!
     
  2. Hoople

    Hoople Account Removed

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    The 2002 engines may be different but on say my late model 96, if the cam support plate is installed, there is no place you can place the dial indicator. The portion of the crank that exits the cam plate for the gear is "D" shaped and can't be used to check run out.

    In my eyes I would want the crank supported by the bearing journals (which it is),, then have the cam plate off, and place your dial indicator on the ground surface of the crank that rides or mates to the cam support plate. That to me would be the best place to be.

    But like I said, maybe the early engines are different. Others may have different ideas also.
     
  3. leedham

    leedham Member

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    Instrument setup for checking engine pinion shaft runout. If runout is
    greater than .003 TIR, Andrews Products recommends NOT installing
    gear drives without first re-truing flywheels to remove excess runout.
    Cam support plate MUST be installed for this test

    I found the above info just now.
     

    Attached Files:

  4. Hoople

    Hoople Account Removed

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    How much runout are you going to measure if your supporting the crankshaft at that point with the cam plate? I don't care what they say. You are hiding some of the runout by supporting the crankshaft in that fashion. It would almost be HARD to exceed .003" while supporting the crank shaft with the cam plate installed.


    I am not throwing any rocks at the manufacture, but if I was in the business of selling gear drives, that is exactly how and where I would tell you to check it.
     
  5. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

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  6. Hoople

    Hoople Account Removed

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    I did not read it but the picture is same as the Thumbnail. It's not the right way based on just the picture. What am I missing.

    Does the cam plate actually have a bearing surface that supports the crank? If it does not, then that way will work.
     
  7. leedham

    leedham Member

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    All good input !!!
     
  8. Hoople

    Hoople Account Removed

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    I mean why would you ever want to support the crankshaft at the point your measuring it at? Makes little sense other than Andrews wants to smooth out the numbers in order to encourage sales.

    Now IF the supporting hole in the cam plate was larger than the ground surface of the crank, and you were using the cam plate only as a support for the dial indicator, then yes that would be the PERFECT way to do it. I have never had a cam plate off to see if the crank hole in the cam plate does actually support the end of the crankshaft.

    If you really want the low down, give Brian at Revolution Performance a call and ask him how and where they measure cranks for runout. They are in the business of fixing cranks. Their on the "other side" of this fence.:)
     
  9. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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  10. Hoople

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    TQ, Thanks for the clarification. If no support bearing, I wonder why Andrews insists on using the Cam support plate? Does not make a lot of sense to me.The last video is a good example and he would get the same measurement (.005") in either case..