1994-11-01

Procedure to the Modification of a Camshaft Cam Lobe Profile 942407

This paper shows a “manual method” to develop a cam lobe profile, modifying a existing profile, to hit some difference like the lift or event.
Employing a micro computer and a worksheet software, we can build a table with cam parameters like acceleration, velocity, lift, area under the positive and negative acceleration curve, curvature radius, etc… all on the degree of the cam lobe.
Modifying the acceleration values it is necessary to achieve the equality of the positive and negative areas, hitting a new profile with lift and / or event modified. The modification of the acceleration table must be followed by the visualization of its derivative, or jerk, to assure a smooth curve to both sides of opening and closing cam.
This paper does not cover such areas as: limitations on acceleration and decceleration values or jerk factors, cam-tappet stress and cam-tappet pattern run-off.
The modification of a cam lobe profile must be followed by the knowledge of some values to avoid the deterioration of valve train dynamics.

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