Precision Engineering Cam design has come a long way since the old days of the simple harmonic design. This design deter-mined the cam shape by using three separate radii - the nose radius, the flank radius, and the base circle radius. Today, this simple method is considered primitive because of the difficulty encountered in accurate inspection, and its poor highspeed performance qualities. The Racing Cam Series Isky Hi-Rev Series cams are manufactured from the finest, high quality Proferal Cast Iron Billets. Combined with mechanical (solid) lifters, they are extremely popular for high-performance dual purpose and competition engines.