MAHLE 42291CP Engine Piston Ring Set - Premium CP-Series Performance Rings

The MAHLE 42291CP is a premium engine piston ring set engineered to meet or exceed original equipment specifications. MAHLE is the world's leading piston ring manufacturer, delivering the most technically advanced and extensively tested piston rings in the automotive aftermarket.

Key Features:

• Pre-lapped for instant seating — virtually eliminates break-in time and gets your engine up to full compression faster
• Plasma-moly or HV385 coated top ring — optimized ring face coating for superior wear resistance, reduced friction, and extended service life
• Barrel-faced compression ring contact area — promotes more efficient compression and improved cylinder sealing
• CNC-controlled gap chamfer — optimizes compression and reduces blow-by for improved power output
• Reverse-twist intermediate rings — engineered for better groove side sealing and enhanced taper-race contact
• CP-20 oil ring assembly — features an exclusive 20-degree ear angle for the best possible side seal against the cylinder wall, with a special chemical polish on the expander for enhanced oil drain-back
• SAE 9254 high alloy steel base material — delivers higher tensile and yield strength, extended fatigue resistance, and increased hardness to withstand extreme firing pressures
• Ring materials, coatings, and tension are all application-optimized for reduced friction and long service life

MAHLE piston rings are driven by OE requirements — reducing friction and ring mass while minimizing engine oil consumption and providing longer service life. The 42291CP set is the ring of choice for professional engine builders performing quality rebuilds.