Cast Piston KitProX piston designs are usually similar to the OEM/stock configurations, although sometimes these designs are adjusted whenever the ProX engineers discover an opportunity for increased performanceProX cast pistons are very stableProX cast pistons are made through gravity casting using aluminum alloy with approximately 18 percent silicon contentSilicon plays a vital role in ProX’s cast piston manufacturing, as it decreases thermal expansionProX two-stroke pistons are manufactured for both cast iron cylinder bores and Nikasil cylinder boresRegarding Nikasil cylinder bores, ProX offers a variety in oversizes graded in A/B/C/D sizing, each going up 0.01mm in diameter