Perf. Piston Ring Set V8 4.040 Bore 1.2x1.5x3.0

The NPR Performance Piston Ring Set V8 4.040 Bore 1.2x1.5x3.0 is engineered for high-performance V8 engines requiring precise ring gap and tension control. Built for serious engine builders and performance enthusiasts, this ring set addresses the critical need for reliable compression sealing and oil management in modified and racing applications. Whether you're rebuilding a stroker motor, refreshing a tired block, or constructing a competition engine, OEM-spec rings often fall short of the demands placed on high-revving or high-boost platforms.

These NPR rings feature the critical 1.2mm top ring, 1.5mm second ring, and 3.0mm oil control ring geometry designed specifically for 4.040-inch bore applications. The precision-engineered gap and tension profiles ensure consistent sealing across the combustion cycle while minimizing blowby and controlling oil consumption—essential factors when running elevated boost pressure or high rpm. NPR's reputation in the rebuild and racing community stems from consistency and material quality; these rings deliver the dimensional stability needed for tight piston-to-wall clearance and reliable long-term performance without compromise.

This ring set is ideal for V8 engine builders, machine shops, and performance shops restoring or modifying 4.040-bore blocks including many popular big-block and small-block variants. Installation requires proper ring end-gap verification and honing to specification—do not assume OEM bore measurements are sufficient. Pair this set with quality forged pistons, a properly reamed and honed block, and correct ring groove tolerances for optimal results and longevity on the street or strip.