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  1. #1

    Degreed my cam--have some questions

    Degreed my cam. Can someone who knows what they are doing take a look at the cam profiles. Did I calculate the valve openings, closings, centerline, etc. correctly? The cam was installed locked with the crank locked. Should I advance or retard the cam timing based on the graph?

    Thanks,

    Mark
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  2. #2
    This will become a sticky! Mark wants holeshot!

  3. #3
    performance enthusiast AD4342's Avatar
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    Calling Nils888...are you there?

    Mark..wow interesting work!!!!

    I am sure Nils888 can answer you. he is a professional engine builder and I am sure he can help you. Hope he see's this post and chimes in with some knowledge.


  4. #4
    The most interesting man in the world. Nils888's Avatar
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    Hay mark. Where are you cheking the valve lift? On top of the rocker arm or at the retainer?? Intake specs looks rite! Exhaust specs don't look rite.
    Are these specs @ .050 of valve lift?

    I would run that cam 2 degrees advanced.

  5. #5
    Pic is attached of where I am checking valve lift. Yes, at the top of the rocker. The graph is from when lift occured on the intake and exhaust rockers. On the graph the point where .050 lift occured is marked. The calcs on the top of the page are at .050 lift. I'm not sure if I calculated the readings at the top of the page correctly. Attached are the actual readings I took in spreadsheet form.

    Thanks

    Mark
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  6. #6
    The most interesting man in the world. Nils888's Avatar
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    The only numbers that look wrong are the exshast centerline.

    Go To www.webcamshafts.com and look up dialing in cams. It will tell you how to calculate lobe centers

    Otherwise all the numbers look rite. Check you valve to piston clearance at overlap!!! That will get your attention!!!

  7. #7

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    Oops...

  8. #8
    GTXX's Avatar
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    Quote Originally Posted by Nils888 View Post
    The only numbers that look wrong are the exshast centerline.
    would that explain the 4degrees of overlap?
    was thinking it would be at least 40 something degrees....

  9. #9
    Quote Originally Posted by Mark S View Post
    Degreed my cam. Can someone who knows what they are doing take a look at the cam profiles. Did I calculate the valve openings, closings, centerline, etc. correctly? The cam was installed locked with the crank locked. Should I advance or retard the cam timing based on the graph?

    Thanks,

    Mark
    mark
    did you pump up the lifters before checking this stuff?. if the lifters are not fully pressurized with oil you will get wonky readings.
    based on your numbers i get 118.5 lobe center for the intake and 114 lobe center for the exhaust.

    mark

  10. #10
    speedskixp's Avatar
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    Quote Originally Posted by rotax racing View Post
    mark
    did you pump up the lifters before checking this stuff?. if the lifters are not fully pressurized with oil you will get wonky readings.
    based on your numbers i get 118.5 lobe center for the intake and 114 lobe center for the exhaust.

    mark
    Hey, English please! WTF does wonky mean? Some sort of canadian slang?

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