Perf. Piston Ring Set V8 4.055 Bore 1.5x1.5x3.0

The Perf. Piston Ring Set V8 4.055 Bore 1.5x1.5x3.0 is a precision-engineered ring set designed for high-performance V8 engines requiring robust compression sealing and oil control. Built by NPR, a respected name in OEM and performance engine rebuilds, this ring set is engineered for builders and mechanics tackling serious engine work—whether you're refreshing a tired block or building a stroker platform from the ground up. The 4.055-inch bore specification makes this set ideal for classic muscle cars, modern performance rebuilds, and any application demanding reliable ring sealing at elevated compression ratios and RPM.

The 1.5x1.5x3.0 ring geometry—top compression ring at 1.5mm, second ring at 1.5mm, and oil ring at 3.0mm—is a time-tested configuration that balances compression sealing, blowby reduction, and oil return efficiency across the entire RPM band. The top compression ring seats quickly for fast ring seal, while the tapered second ring manages blow-by and heat without excessive friction. The 3.0mm oil ring provides superior oil control on the cylinder wall, critical for maintaining film strength during sustained boost or high-load operation. NPR's manufacturing tolerances ensure consistent bore-to-ring fit, minimizing flutter and micro-welding risk during critical break-in phases.

This ring set works across a wide spectrum of V8 platforms—big-block Chevy, small-block performance variants, and purpose-built race engines—provided bore diameter matches the 4.055-inch specification exactly. During installation, verify piston-to-wall clearance and ring end-gap using a feeler gauge; proper gap spacing (typically 0.004–0.006 inches per inch of bore) is essential for preventing ring stiction or blow-by leakage. Pair with quality honing for optimal cross-hatch surface finish and maximum ring seating speed. Whether you're rebuilding for street duty or track use, the Perf. Piston Ring Set V8 4.055 Bore delivers the compression geometry and manufacturing precision that serious engine builders depend on.