Piston Ring Set 4.135 Moly 1.2 1.5 3.0mm

The JE PISTONS Piston Ring Set 4.135 Moly 1.2 1.5 3.0mm is a file-fit piston ring kit engineered for eight-cylinder high-performance and racing engines. This Pro Steel Series ring set features plasma-coated moly construction paired with low-tension design, delivering optimized compression sealing and reduced friction across the entire RPM range. Built for precision fitment and durability in demanding engine builds, this piston ring set serves serious engine builders, hot rod enthusiasts, and racing professionals who demand exact tolerances and proven reliability.

The 4.135-inch bore diameter specification positions this ring set for mid-sized displacement engines common in street performance, bracket racing, and vintage restoration applications. The 1.2mm top ring, 1.5mm second ring, and 3.0mm oil ring configuration represents a traditional three-ring design optimized for compression retention and oil control. The low-tension profile reduces parasitic drag on the crankshaft, improving power output and fuel economy compared to conventional high-tension designs. Plasma moly coating enhances wear resistance and reduces bore scoring during break-in, critical for extended engine longevity and consistent ring seal.

File-fit rings require precision honing of the bore to match exact specifications—this is standard practice in competition and professional engine work. The eight-cylinder configuration accommodates V8 engines and inline-eight applications across multiple displacement ranges. This ring set integrates seamlessly with OEM and custom piston combinations where bore diameter matches specification. Builders selecting a 4.135-inch bore diameter will find this kit delivers the steel ring construction and moly technology proven in endurance racing and high-revving street engines.