Race Master, and the Pro Flo versions identified as Race Flo valves, are manufactured of XH-426 material for the exhausts and NK-842 for the intakes. This series of valves is targeted at the bracket, drag and oval track racers operating below 8000 rpm - above which engine speed titanium valves are generally required. Any engine builder successfully using EV-8 alloy ( 21-4N ) valves will find in this series of Manley valves a superior piece at a most attractive price. The Ultimate Tensile Strength charts on this page and the next, show the Manley Race Series to be equal to the best that the competitors have to offer. XH-426 Stainless Exhaust Material. NK-842 Stainless Intake Material. Chrome Stems and Hard Tips. Swirl Polished and Machined. Intakes are Pro Flo for Improved Flow. O.E. Style Radius Keeper Grooves.
