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  1. #1

    Cylinder Compression

    Results from a compression check:

    Cyl 1: 150 psi
    Cyl 2: 160 psi
    Cyl 3: 120 psi

    Running stage 3 with all the fruit.

    Is this acceptable, engine has approx 20 hours on it. If it's not okay what do I need to do to check/fix?

  2. #2
    speedskixp's Avatar
    Join Date
    Feb 2008
    venice fl.
    hmmm. Are you doing the compression test with a worm motor holding the throttle wide open? If not you need to. Compression is high on 1 and 2 and low on 3. Strange! What kind of gauge are you using?

  3. #3
    Engine is cold and WOT
    Gauge is brand new Snap-on so shouldn't ba an issue.

    I just installed a cam but that shouldn't effect the comp as all valves should be closed to get a reading

  4. #4
    speedskixp's Avatar
    Join Date
    Feb 2008
    venice fl.
    The cam timing will effect the compression. I suspect that is why your 1 and 2 cylinders are high. You want to set your cam timing so that you compression is at 130-135 with rr cam and about 140 with stock cam. Cam timing will fix you 1 and 2 high compression but that number three cylinder is not looking good. If you can, test the compression again with the motor warm.

  5. #5
    It's a stock cam so I will advance it a bit and check again, currently it's running retarded.

    And I'll do it warm

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