Perf. Piston Ring Set V8 4.040 Bore 1.5x1.5x3.0

The Perf. Piston Ring Set V8 4.040 Bore 1.5x1.5x3.0 from NPR Piston Rings is engineered for serious engine builders and performance enthusiasts who demand precision-fit components for high-output V8 applications. Whether you're rebuilding a stroker engine, upgrading to a larger bore diameter, or restoring a classic muscle car engine to original specifications, this ring set delivers the exact geometry required for optimal compression and durability. A 4.040-inch bore represents a popular oversized configuration for big-displacement V8 engines, requiring rings manufactured to exacting tolerances that factory sets cannot match.

This piston ring set features a 1.5x1.5x3.0mm ring profile—comprising two compression rings (top and second) at 1.5mm thickness and a 3.0mm oil control ring—a geometry that balances blow-by control with reduced friction and improved oil return. The NPR ring design minimizes radial wall thickness while maintaining superior conformability to worn or non-round cylinder bores, critical for vintage engine work or unconventional machining. Modern performance ring materials resist scuffing and wear across wider temperature ranges than OEM rings, supporting aggressive cam timing, higher boost levels, and extended power band operation without accelerated ring land wear or excessive oil consumption.

This ring set is ideal for LS-based engines, big-block Chevy strokers, and other V8 platforms bored to 4.040 inches or larger. Installation requires precise ring gap clearancing and careful ring land inspection during piston assembly—best performed by experienced engine builders with proper ring filing equipment. Verify piston pin diameter, compression height, and top ring land geometry against your specific pistons before ordering, as ring sets are application-specific and non-returnable once custom-fitted.