Perf. Piston Ring Set V8 4.005 Bore 1.2x1.2x3.0

The Perf. Piston Ring Set V8 4.005 Bore 1.2x1.2x3.0 is engineered for serious V8 engine builders and mechanics seeking OEM-grade replacement rings or high-mileage engine restoration. These NPR PISTON RINGS deliver the compression seal integrity that modern performance and stock rebuild applications demand, whether you're refreshing a tired block or assembling a street-strip powerplant. This complete 8-cylinder ring set eliminates the guesswork of sourcing individual ring profiles and ensures consistent blowby control across all eight cylinders.

Built from hardened steel with a nitride finish, this piston ring set features the proven 1.2 x 1.2 x 3.0 mm dimensions that provide optimal balance between sealing efficiency and ring-to-groove clearance for 4.005-inch bore V8 engines. The standard-tension design minimizes friction loss while maintaining reliable ring-to-wall contact, preventing oil consumption and combustion gas escape during both cruise and full-throttle operation. The nitride coating enhances wear resistance and reduces scuffing during break-in, critical for protecting cylinder walls during the first heat cycles of any freshly honed or re-sleeved block.

This ring set fits American V8 engines with a 4.005-inch bore diameter—covering classic big-blocks, LS-series platforms, and traditional small-block variants that fall within this bore size range. Professional rebuilders and DIY enthusiasts alike trust NPR's American V8 Engine Ring Series for consistent quality that meets OEM specifications without premium pricing. Proper installation requires careful end-gap verification (critical for thermal expansion), correct ring orientation per manufacturer marks, and application of assembly lube to avoid damage during piston-rod installation into freshly bored cylinders.