Sportsman Stainless 1.570" exhaust valves 5.450 length and 8mm stem. COMP Cams Sportsman Valves are available in a variety of diameters stem sizes and lengths for street and Competition engines. The stainless Steel valves are made from 21-4N forged Steel alloy with 50 HRC minimum hard tips (eliminates lash caps); these valves deliver tremendous performance and durability. The hard chrome-plated 11/32" stems utilize proprietary oil retention surfacing and feature a single bead lock groove.