Superior quality high-silicon aluminum produces pistons that are extremely durable, have excellent resistance to scuff and seizure, and resist cracking in high heat areas. OEM constructed flat top pistons have 4-valve reliefs, and the piston skirts are diamond machined to assure that clearances are half that of industry standards. Compression ratios are 10.6:1 with 58cc combustion chambers, 9.9:1 with 64cc combustion chambers and 8.7:1 with 76cc combustion chambers. 5/64'', 5/64'', 3/16'' ring grooves.
