[Barry_R]

Stuff can happen.

But given the number of parts I handle here I have to say that Diamond does not goof up very often. Like pretty close to never - maybe three sets wrong in four years, and hundreds of sets. The radial wall thickness on a ring and could be concievably done wrong if the programming was left in place for a reduced radial ring pack on some custom piston. But your piston is a catalog part and the programming should be locked down pretty well.

If the ring groove was indeed wrong, they should not be lathe cut by somebody. The pistons should be replaced. Ring grooves are more accurate than ANY common machine lathe can duplicate, they are not perpendicular to the centerline - vertical uptilt of +/- one degree is common, and they need to have at least a .010 internal radius to prevent fracture. Unless your machine shop does NHRA Pro Stock or NASCAR stuff he cannot duplicate that even if he tries.

Reduced radial wall rings work very, very well. Most ring manufacturers can suppply them for several bore diameters. Mahle makes an excellent piston ring - manufactured by their Co-Fap division in Brazil. Mahle also owns Perfect Circle, who makes an equally good ring. Federal-Mogul makes an equally good ring. Total Seal PURCHASES their plasma-moly ductile iron based rings from either Perfect Circle, Federal-Mogul, or Co-Fap. Same parts. Different boxes.