[Barry_R]

Since we are working on development of a comparable product I will not comment on the entire paragraph of the ZDDP+ info - - other than to point out that the .0002 cam wear number is likely inaccurate. The chemicals needed are still readily available....

Flat tappet cam cores are flame hardened on rollers at the CWC casting plant before shipping to the two major grinding companies - all in Michigan. The hardness depth has to be enough to allow multiple grinds from a single blank - and is far, far deeper - more likely over .100".

The taper on a cam lobe is what casues lifter rotation and is normally expressed in degrees over a specified distance as measured by an Adcole guage machine. Lacking the ability to measure that with normal tools, we'll expect to see between .001-.002 of taper over the width of a common cam lobe. Once that taper has worn away the lifter will cease to rotate and failure will occur from sliding contact.

Since the interface between cam & lifters is the critical item its hard to get that nailed every time with a machine. All he can do is duplicate what the block is "supposed to be" and cannot duplicate any variances from spec regarding lifter bore placement or angle.

Most of the advice given here is reasonable accurate. I would not worry about Top Fuel engines - they use roller cams. Pull the inner springs out.