MAHLE 42082CP.040 Plasma-Moly Piston Ring Set Bore Oversize - 4.105in 040 8-Cylinder

The MAHLE 42082CP.040 is a premium plasma-moly piston ring set designed for 8-cylinder engines with a 4.105-inch (+0.040" oversize) bore diameter. MAHLE Original piston ring sets are designed to be installer-friendly — pre-lapped to seat immediately, virtually eliminating break-in time, with ring materials, coatings, and tension all optimized for reduced friction and extended service life.

MAHLE piston rings utilize an SAE 9254 high alloy steel base material, delivering higher tensile and yield strength, extended fatigue resistance, and increased material hardness.

Key Features:

• Compression rings feature a barrel-faced contact area for more efficient compression and CNC-controlled gap chamfer to optimize compression and reduce blow-by.
• Intermediate rings use a reverse twist design for better groove side sealing and taper race machining to enhance contact.
• CP-20 oil ring assemblies feature an exclusive 20-degree ear angle for the best possible side seal against the cylinder wall, plus a special chemical polish on the oil ring expander for enhanced oil drain-back.
• Top ring material: carbon steel with plasma-moly face coating; second ring material: cast iron; oil ring assembly material: stainless steel. Ring groove style: shallow groove.
• Ring thickness: 1.5mm / 1.5mm / 2.5mm (top / second / oil)
• Oversize: +0.040" | Bore Diameter: 4.105 in.
• Sold as a complete 8-cylinder set

MAHLE is the largest piston ring manufacturer in the world, and MAHLE Original piston rings are the most technically advanced in the industry, driven by OE requirements to reduce friction and ring mass while minimizing engine oil consumption and providing longer service life.