MAHLE 4055MS-15D Performance Piston Ring Set 4.055 in. Bore 1.5mm/1.5mm/3.0mm Drop-In

The MAHLE 4055MS-15D is a performance drop-in piston ring set designed for a 4.055-inch bore with a 1.5mm / 1.5mm / 3.0mm ring thickness configuration. Engineered using MAHLE's industry-leading piston ring simulation and computer development tools, these rings are built to deliver maximum sealing efficiency while minimizing friction for real, measurable power gains.

These drop-in rings require no additional filing or end-gap preparation, making them ideal for engine builds where convenience and precision are equally important. The ultra-flat ring flanks are precision-machined to maximize ring-to-piston groove contact and sealing integrity throughout the RPM range.

Key Features:

• Bore Size: 4.055 inches (102.997mm)
• Ring Pack Configuration: 1.5mm top ring / 1.5mm second ring / 3.0mm oil ring
• Top Ring: Positive-twist ductile iron, barrel-faced with plasma-moly inlay for superior scuff resistance and durability
• Second Ring: Reverse-twist tapered-face cast iron, phosphate coated for improved oil control and combustion gas management
• Oil Ring: 3-piece standard tension design for effective oil control
• Drop-In Fit: Pre-gapped for direct installation — no file fitting required
• Sold as: 8 complete sets (full V8 engine kit)

MAHLE performance piston rings are trusted by professional racing teams worldwide and backed by decades of motorsport engineering heritage. The plasma-moly top ring coating provides exceptional durability under high heat and pressure, while the standard-tension oil ring pack reduces parasitic drag for improved efficiency and longevity.