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Thread: Converting Between Gen I and Gen II Cam Angles

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    Senior Tuner CCS86's Avatar
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    Converting Between Gen I and Gen II Cam Angles

    When trying to compare cam angles between Gen I and Gen II Coyotes (mid-lock phasers), is it just a static angle shift of half the phasing range?

    Thanks!

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    Senior Tuner veeefour's Avatar
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    Mid-lock is your baseline hence the IVO goes only -20 max.

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    The Gen 1 cars don't have their base positions in the 720* range defined, making converting/ comparing them, exactly, difficult. When you plot it out you see the intake cams are not moving that much differently, and you can get an idea that the base values of the gen 1 cars intake is some where around 370*, and thats probably the same as the exhaust.

    0*-180*= power
    180*-360*= exhaust
    360*-540*= intake
    540*-720*= compression

    A sheet with a simple visual representation of whats happening. Its got its limitations, but as long as you stay with in reason it works fine.

    Current OP Cams with doughnut chart.xlsx
    Last edited by murfie; 01-30-2020 at 03:24 AM.

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    Senior Tuner CCS86's Avatar
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    Quote Originally Posted by veeefour View Post
    Mid-lock is your baseline hence the IVO goes only -20 max.


    That's how I first thought of it, but since the range of a Gen I is 50*, that would make the comparison look like this, right?:

    Intake Exhaust
    Gen I 0 0
    Gen II 25 -25


    Intake Exhaust
    Gen I -50 50
    Gen II -25 25




    But then, there is the possibility that the cams are mechanically timed differently (which I thought I heard that they were), or that the total phasing range is different.

    "[ECM] 38180 - VCT Intake Cam Advance Phasing Limit vs. RPM vs EOT" and "[ECM] 38179 - VCT Intake Cam Retard Phasing Limit vs. RPM vs EOT" have the intake cam range at +/- 50*, which seems wrong.

    "[ECM] 20609 - VCT Exhaust Cam Phasing Limit vs. RPM vs. EOT", is the one table for exhaust cam, and has 46.75*



    If we just look at idle condition, which I would expect to have similar cam angles:

    Gen I: MP0 = 0* int / 0* exh

    Gen II: MP1 = 20* int / 0* exh

    So, either they have significantly changed the actual cam angles at idle, or there is asymmetry to the cam positions between generations.

    What am I missing?

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    Senior Tuner CCS86's Avatar
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    Quote Originally Posted by murfie View Post
    The Gen 1 cars don't have their base positions in the 720* range defined, making converting/ comparing them, exactly, difficult. When you plot it out you see the intake cams are not moving that much differently, and you can get an idea that the base values of the gen 1 cars intake is some where around 370*, and thats probably the same as the exhaust.

    0*-180*= power
    180*-360*= exhaust
    360*-540*= intake
    540*-720*= compression

    A sheet with a simple visual representation of whats happening. Its got its limitations, but as long as you stay with in reason it works fine.

    Current OP Cams with doughnut chart.xlsx



    Thanks for that spreadsheet murphie.

    Even without the Gen I base positions defined in the calibration, can't we use the physical cam timing procedure to figure that out?

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    Senior Tuner veeefour's Avatar
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    Quote Originally Posted by CCS86 View Post
    But then, there is the possibility that the cams are mechanically timed differently.
    And they are. You can clearly see it side to side, the timing procedure is also different. 2 gen has more spacing between banks.

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    You should be able to. Using a degree wheel while doing it to check base position of each cam. I think procedure is "set it at 12 o'clock, rotate 180*, rotate 360*" type of directions. So many OPG/CS being replaced, but not much reason to care about the base positions, just getting it back in the same spot it was.

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    Senior Tuner CCS86's Avatar
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    I'm just surprised after 5 years if no one has done that and answered the question definitively.

    I don't have direct access to a Gen II engine right now.

  9. #9
    Senior Tuner veeefour's Avatar
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    Quote Originally Posted by murfie View Post
    You should be able to. Using a degree wheel while doing it to check base position of each cam. I think procedure is "set it at 12 o'clock, rotate 180*, rotate 360*" type of directions. So many OPG/CS being replaced, but not much reason to care about the base positions, just getting it back in the same spot it was.
    More less. Attached for 2 gen.

    On the other hand 3 gen is different again, resembles 1 gen...

    2 gen Coyote cam timing.pdf

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    Has this been verified/updated etc for KNOWN info?
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