Perf. Piston Ring Set V8 4.000 Bore 1.2x1.2x3.0

The Perf. Piston Ring Set V8 4.000 Bore 1.2x1.2x3.0 from NPR PISTON RINGS is engineered for high-performance V8 engines requiring precise bore-matching and proven ring geometry. Whether you're rebuilding a street engine, preparing a weekend racer, or restoring a classic muscle car, this ring set delivers the compression sealing and blow-by control critical to sustained horsepower and oil economy. NPR's reputation in performance engine building makes this set a trusted choice for mechanics and enthusiasts who refuse compromise on engine internals.

The 1.2x1.2x3.0 ring geometry—top ring, second ring, and oil ring dimensions—is optimized for the 4.000-inch bore specification to maintain tight wall contact across the entire piston stroke, minimizing leakage while managing thermal expansion under load. NPR's performance ring sets utilize high-quality steel and precise manufacturing tolerances to withstand elevated combustion pressures typical of modified or boosted engines. The three-piece design separates compression control (top two rings) from oil management (oil ring), ensuring consistent blowby rates and extended engine life even in demanding applications.

This ring set is ideal for V8 engine builders and enthusiasts working with 4.000-inch bore blocks commonly found in small-block Chevy, Ford, and Mopar platforms. Installation requires careful piston-to-bore clearance verification and proper ring-end gap filing to match your specific engine combination; consult your engine builder's specification sheet before assembly. The lightweight 0.75-lb package ships efficiently, and NPR's consistent quality ensures compatibility across matched piston sets and cylinder preparation standards typical of professional machine shop work.