Originally Posted by fast68plymouth
If you’re curious.......
you could try measuring that duration@lift, @ the valve with the full spring load, with lash...... and see how those numbers really look when everything is flexing.


I figure a lot of valvetrain compression on the starting side of the ramps at high rpm. .020 maybe, at max acceleration of the valve? Then momentum will probably lessen that at mid/upper lift to Zero. Then the closing side will see something similar. I am going to google spintron testing and see what pops up.

8..603 156 mph best, 2905 lbs 549, indy 572-13, alky