A .00005 dial indicator is used to CENTER & SQUARE the piston blank to the spindle. The fixture remains in the milling machine vise during all machining operations & no further indicating is necessary. Once centered, the "V" block assures ACCURATE repeated CENTERING & SQUARING of all piston blanks! All piston blanks that are pre-machined are first drilled with a diamond coated faceted drill. Then, they are bored with a pollycrystalline diamond coated boring bar. I "DO NOT" hone this hole to achieve the correct fit. The clearance between the wrist pin & precision bored hole is .0001. This is easily accomplished with gage pins used for sizing. This finished bored hole will become the zero for finish machining the pistons OD, tapered top & piston crown. These finish cuts are all completed once the piston has been zeroed using the wrist pin hole. THE USE OF A "V" BLOCK TYPE HOLDING FIXTURE ASSURES THE WRIST PIN HOLE IS CENTERED AS WELL AS BEING SQUARE TO THE PISTON'S OD! DO NOT OVERLOOK THIS VERY IMPORTANT FEATURE!!
