Piston Ring Set 4.020 Moly 1/16 1/16 3/16

The JE PISTONS Piston Ring Set 4.020 Moly 1/16 1/16 3/16 is a premium race-series engine component engineered for high-performance applications requiring precision bore sizing and extended durability. This 8-cylinder piston ring kit features a plasma-moly coating applied to ductile iron construction, a combination that resists scuffing and wear in sustained high-RPM operation while maintaining consistent compression seal across the ring's service life.

The ring set is sized for a 4.020-inch bore with file-fit installation, meaning the rings are supplied slightly oversized and must be filed to the exact bore diameter during engine assembly. This approach allows builders to achieve optimal ring-to-wall clearance specific to their cylinder honing finish. The three-piece design—1/16-inch top ring, 1/16-inch second ring, and 3/16-inch oil ring—with standard tension characteristics provides balanced blowby control without excessive friction. The ductile iron material offers superior fatigue resistance compared to cast iron alternatives, critical in racing environments where power cycles are rapid and sustained.

This piston ring set is designed for engine builders and machine shops rebuilding competition engines, vintage muscle cars, or marine powerplants where bore size precision and ring quality directly impact reliability and power output. The 4.020-inch bore specification accommodates overbored small-block applications typical in street and track performance builds. File-fit rings demand proper installation technique and honing equipment but reward the builder with superior concentricity and sealing performance compared to pre-sized alternatives.

JE PISTONS manufactures this kit to OEM tolerances and race-proven specifications. The plasma-moly surface treatment reduces initial break-in wear and extends ring life under continuous high-load conditions. Proper installation with a ring compressor tool and careful cylinder wall preparation are essential to achieving the performance potential of this premium ring set.