...If you want to open another can of worms, there is a debate on what part of the lift curve sees the most stress, hence valvetrain deflection. A clue: it's NOT at full lift where spring forces are highest!
...that'd be the 'valve jerk' I believe?
It is the extreme change of mechanical motion that would impart the greatest amount of material stress, therefore I would think the derivate of the acceleration curve would be the answer, thus the 'valve jerk' event.
@Brad_Haak's post with the screenshot shows the relationship of these elements very nicely!!!
