Piston Ring Set 4.285 Moly 1/16 1/16 3/16

The Piston Ring Set 4.285 Moly 1/16 1/16 3/16 (Part J100F8-4280-5) is a premium race-series piston ring kit engineered for high-performance eight-cylinder engines with a 4.285-inch bore specification. This complete piston ring set is ideal for serious engine builders and performance shops preparing racing engines, forced-induction street engines, or high-displacement naturally aspirated builds.

Designed for file-fit installation, the piston rings combine plasma moly coating with ductile iron construction to deliver superior ring life and blowby control in demanding applications. The ring configuration—1/16-inch top ring, 1/16-inch second ring, and 3/16-inch oil ring—follows race-proven proportions that balance sealing efficiency with minimal friction. The plasma moly coating reduces ring wear, extends ring groove life, and improves oil control during extended high-RPM operation.

File-fit rings demand precise honing and installation technique, making them the choice for builders who require exact bore-to-ring clearance control and maximum compression retention. This kit is not a bolt-on component for casual assembly; it requires professional installation with proper honing equipment and clearance verification. The moly-coated construction particularly benefits engines operating under high-stress conditions.