ANDRA Fastlane 20 - Page 13

1 2 Here is a close-up look at the lobes on a Crane blueprint camshaft for a 427/425 HP big block Chevy (part number CRN-1969961). Most flat tappet camshafts have a similar lobe shape. 3 5 Here’s a disassembled Crane solid flat tappet lifter. The inner workings are simple. This is a fully machined tool steel lifter from COMP Cams, designed for use in severe duty NASCAR applications where RPM levels and valve spring loads are high. The body has a Diamond-Like Carbon (DLC) coating that hardens the metal surface to be extremely slick and wear resistant. The lifter internals are actually one piece instead of two as normally found on conventional lifters. Lifters like this are at the super high end of the spectrum, and they aren’t cheap. This is a closeup of a COMP Cams Stock Eliminator camshaft lobe. The lobe shape is more “square” than the lobes on the Crane cam in the previous photo. This allows more radical valve opening and closing rates. 4 See the tiny hole in the base of this COMP Cams solid lifter? It’s been Electrical Discharge Machined (EDM) into lifter base, and is designed to add more lubrication between the cam lobe and lifter face to improve reliability. There are two EDM arrangements available—one centered in the lifter base and one drilled offset. As the lifter spins, the offset hole will lose contact with the cam lobe, but some engine builders have a preference for this design.