102 ? which cam ? I did not see that.
No you cant calculate it on paper
You can measure the valve timing events with a degree wheel after it is installed.
As an example:
284 adv duration, meaning 284/2=142 ea side of int lobe centerline.
Intake @ 110 atdc.
For int opening event:
142-110= 32 btdc. Int opens
For int closing event:
110+143=252; 252-180= 72 abdc.
Compare to the chart.
QED
