Finished rollers & crank pins, both made from full hard (63 Rockwell C) M-2 steel reamer blanks. The rollers are .0627 dia. X .250 length with a .0313 radius on both ends. The radius is ground on each roller end after cutting the roller to length. Full contact length of each roller is .1875. The crank pins are .3283 dia. with the driving pin for the bell valve ground on one end. The crank pins are a .0013 interference fit in a ground hole in the through hardened crankshaft. These crank pins never come out or break & the wear is very low because of the large diameter!!
