Piston Ring Set 4.000 1.2 1.5 3.0mm

The Piston Ring Set 4.000 1.2 1.5 3.0mm is a precision engine component designed for rebuilds and performance restoration on 4-inch bore engines. This ring set addresses one of the most critical wear points in any internal combustion engine—the sealing interface between piston and cylinder wall. Whether you're performing a complete overhaul after high-mileage operation or building a modified engine for enhanced compression and power delivery, this set provides the precision fit and material quality that serious mechanics demand.

This piston ring set features a three-ring configuration with precisely engineered gaps: a 1.2mm top compression ring, a 1.5mm secondary compression ring, and a 3.0mm oil control ring. Each ring is manufactured from high-strength alloy steel with controlled wall thickness and surface finish to ensure proper tension against the cylinder wall, maintaining gas sealing during the combustion stroke while minimizing friction losses. The 4.000 inches bore specification ensures correct fitment on engines with that exact piston diameter, a critical measurement that directly affects compression ratio, sealing efficiency, and ring stability during acceleration and peak combustion pressure.

Engine builders and mechanics will benefit from this piston ring set, especially when disassembly has revealed ring wear, blow-by, or compression loss. Its design is suitable for both standard rebuilds and performance applications, ensuring that the engine operates efficiently under various conditions. This set is an essential component for anyone looking to maintain or enhance the performance of their 4-inch bore engine.