Mopar Cam- how many more degrees @.006 to equal at .200?
FWIW.... how curve plots and some basic processing can help to understand the cam better.
Here is a plot of a cam for a 4 banger cam that I took recently: it's an older Isky grind for a hydraulic lifter. The bottom graph is the lobe lift; the upper graph is the velocity. The slope (steepness) of the velocity curve is the acceleration; the steeper the velocity curve, the higher the acceleration. (And it would not be hard add a graph of the lobe acceleration.)
The .050' lobe lift point is at 5 degrees ATDC, so the hardest acceleration is almost all before the .050" point. That is not so obvious from just the lift curve.
BTW, the actual valvetrain lift gets modified from the direct lobe lift vale as the lobe on lifter contact point moves out from the center as you move up the ramp. This data was measured off of the lifter, so it actually reflects the lift/velocity/acceleration on the valvetrain.
So that begs a minor question of whether the cam mfr's measure lift directly off the lobe or with the appropriate sized lifter. Maybe wyrm can answer this....??
FWIW.... how curve plots and some basic processing can help to understand the cam better.
Here is a plot of a cam for a 4 banger cam that I took recently: it's an older Isky grind for a hydraulic lifter. The bottom graph is the lobe lift; the upper graph is the velocity. The slope (steepness) of the velocity curve is the acceleration; the steeper the velocity curve, the higher the acceleration. (And it would not be hard add a graph of the lobe acceleration.)
The .050' lobe lift point is at 5 degrees ATDC, so the hardest acceleration is almost all before the .050" point. That is not so obvious from just the lift curve.
BTW, the actual valvetrain lift gets modified from the direct lobe lift vale as the lobe on lifter contact point moves out from the center as you move up the ramp. This data was measured off of the lifter, so it actually reflects the lift/velocity/acceleration on the valvetrain.
So that begs a minor question of whether the cam mfr's measure lift directly off the lobe or with the appropriate sized lifter. Maybe wyrm can answer this....??