Perf. Piston Ring Set V8 4.120 Bore 1.5x1.5x3.0

The Perf. Piston Ring Set V8 4.120 Bore 1.5x1.5x3.0 is a precision-engineered ring package designed for high-performance V8 engines requiring exact bore specifications and optimized compression. Built for serious engine builders and mechanics who demand reliable sealing under sustained horsepower, this NPR piston ring set addresses the critical need for proper gas containment, blow-by reduction, and oil control in modified or rebuilt V8 applications. Whether you're running a stroker build, a naturally aspirated performance engine, or restoring a vintage big-block, the correct ring set is foundational to engine longevity and power delivery.

This piston ring set features a 1.5mm top ring, 1.5mm second ring, and 3.0mm oil ring configuration—a classic three-piece design that maximizes sealing efficiency while minimizing friction losses. The 4.120-inch bore specification ensures a precise fit in cylinders bored to that diameter, preventing ring flutter and maintaining consistent pressure across the combustion chamber. NPR's manufacturing process delivers tight tolerances and controlled gap dimensions, critical factors that prevent excessive blow-by at high RPM and protect against oil consumption issues that plague inferior ring sets. The balanced design works in concert with proper ring gaps and honing to achieve the compression and power output your build demands.

This ring set is ideal for engine builders, performance shops, and experienced mechanics assembling 4.120-bore V8 engines ranging from street performance to competition applications. Installation requires careful attention to ring gap measurement, proper cylinder honing to specification, and correct ring positioning on the piston—factors that directly influence oil control and blow-by rates. Compatibility is limited to pistons and cylinders dimensioned for 4.120-inch bore; verify your engine's exact bore diameter before ordering. Used alongside quality pistons, rods, and proper assembly techniques, the Perf. Piston Ring Set V8 4.120 Bore delivers the sealing performance expected from a professional-grade component.