Lifter re-ginding or turning

[Hotrodpaul]

Yes, they are ground with a convex face and the cam has a slight taper so that the lifter will rotate. As the lifter wears, the face will become flat or even concave, and at that point, the lifter/Cam combo won't last much longer. Since I have access to a CNC lathe, I can program a convex radius and re-machine the face to be used with a new or nicely used cam. This is a big problem with original flat tappet GM cams as they tend to wear quickly even with stock valve springs. My survivor 69 Z-28 had some concave lifters after 44K miles with the tops of several cam lobes starting to wear. I plan on trying to re-machine used lifters and see how they work. I had heard the lifters were ground on a 12-18" radius but need some verification. I could measure some new GM lifters on a surface plate with a height gauge to see how much higher the center is than the edge. Then do a cad layout to determine the radius.

Paul