Original H-O's Camshaft
Lobe Profile Calculator #1

This calculator computes a "best fit" curve approximating the actual lift profile of the specified camshaft lobe. Using the resultant cam lobe profile, the calculator then computes the duration at each 0.050in increment of valve lift (computed from lobe lift times rocker ratio minus any valve lash) from 0.100in to less than or equal to max valve lift. It also calculates the duration at advertised lift, .050, and .100 increments to maximum lobe lift. For a "good fit", the input durations at .050 and .200 should be very close to the calculated durations at those lifts.

Pick a Cam type, pick a Lobe Use, then pick a Lobe profile or input your own. If desired, change rocker ratio. Then click Compute curve button.

NOTE: "Ctr line" is listed for the cam selected, but it is ignored in this program as it does not affect the output. This value is used in other H-O calculators.


Duration at:
Tappet lift: Valve lift:
Advert: 0.100in:
0.050in: 0.150in:
0.100in: 0.200in:
0.200in: 0.250in:
0.300in: 0.300in:
0.400in: 0.350in:
0.400in:
0.450in:
0.500in:
0.550in:
0.600in: