Lifter re-ginding or turning

[VintageMusclecar]

Different manufacturers used different radii. There are numerous variables that come into play re: the radii, hence the large variances between manufacturers.

A flat tappet lifter <span style="font-weight: bold"><span style="font-style: italic"><span style="text-decoration: underline">MUST BE</span></span></span> ground with a radius or it will cause cam/tappet failure. Flat tappet lobes are ground with a slight taper to them to facilitate lifter rotation--no rotation = failure. (side-note: this taper also causes a flat tappet camshaft to be forced towards the rear of the engine while running, which is why there is no need for a thrust button/plate when using a flat tappet cam. A roller profile does not have any taper ground in, and as such the cam would be free to move back &amp; forth in the engine while running--definitely <span style="font-weight: bold">NOT</span> a good situation. This is why roller tappet engines utilize either some sort of thrust plate or a thrust button.)

Anyhow, that and a $5.00 bill will get you a cup of joe @ your favorite bistro.