Federal-Mogul designs and engineers pistons to meet the most demanding street performance and racing conditions. In combination, we draw upon more than 100 years of Federal-Mogul engine mastery to enhance the piston ring and its seal. Our Speed-Pro® brand is recognized for being a winner in every form of racing, and is the proven horsepower leader in oval track and drag racing. Hell Fire® Rings: Speed-Pro Hell Fire rings, manufactured from a specially hardened and tempered ductile iron alloy, are engineered to thrive in extreme racing conditions. These rings retain tension under the most brutal operating conditions, including engines that rely on megadoses of nitrous oxide. Proven in Pro Street, IHRA Pro-Mod and NHRA Top Fuel & Funny Car racing, Hell Fire rings will not flake, and the SS-50 oil rings keep chambers dry, preventing detonation. Claimer Series Rings: Speed-Pro Claimer Series piston rings are designed for oval-track "claimer" engines, bracket racers and street performance applications. Claimer Series piston rings provide a choice between standard cast top rings and molybdenum-faced beveled top rings for high-RPM sealing. The rings come with SS-50® stainless steel oil-control rings and a taper-faced second ring that aids in oil control and allows an escape path to reduce inter-ring pressure.Pit Stop USA offers Speed-Pro Claimer Piston Ring Set - Plasma-Moly - 4.000" Bore - 1/16" - 1/16" - 3/16" Thickness - 8-Cylinder - Set of 8 R6902 at low everyday prices. Be sure to check out all of our products from Speed Pro including Speed Pro Speed-Pro Claimer Series Piston Rings.