Timing chain slack check

Small Block Mopar Engine

  1. Kllrbee

    Kllrbee Well-Known Member

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    Hey guys,
    Im picking up a new (to me) 340 car this weekend. Im going to do a basic run thru of the motor when I get it without pulling it from car. Just timing, comp test, carb tuning, etc.
    I havent checked the slack of a timing chain while motor was in the car in about 25 years. Just checking to see if I remember how to do this correctly.
    Line up crank with timing marks at zero, then reverse direction about 10 degrees while looking to see when rotor moves? If moves before, good. If barely moves, too much slack.
    Sound about right?
     
  2. abdywgn

    abdywgn dismantler

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    yes. but they pull so good at the top end...you just have to keep cranking the initial timing up to get 'em started.
     
  3. moper

    moper Well-Known Member

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    Yeah. I don't worry about the TDC. turn it counterclockwise about 1/4 turn, then pull the ignition cap, and turn the engine by hand clockwise very slowly. If the crank moves more than a few degrees before the rotor turns, it's got some wear. May not be "shot", but there's wear in the chain and possibly the oil pump drive and bushing.
     
  4. Kllrbee

    Kllrbee Well-Known Member

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    Ok, thnx guys. Like I said, been a lil while since checked that way.
    Forget TDC, got it...very easy.
    Thnx again
     
  5. nm9stheham

    nm9stheham Well-Known Member

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    You will for sure feel 3-4 degrees of slack/retarded timing in off-idle and mid range performance.
     
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