MAHLE 42086CP.040 Premium Plasma-Moly Engine Piston Ring Set Over - 0.040

The MAHLE 42086CP.040 is a premium engine piston ring set ground to +0.040" oversize for use in engines with bored or worn cylinders that have been machined to that specification. As the world's largest piston ring manufacturer, MAHLE engineers these rings to meet or exceed original equipment standards, delivering reliable compression, superior oil control, and long service life.

MAHLE's CP-series ring sets are designed to be installer-friendly and arrive pre-lapped, allowing the rings to seat immediately and virtually eliminating traditional break-in time. Ring materials, coatings, and tension values are precisely optimized for reduced friction and extended durability in each specific application.

Key Features:

• +0.040" Oversize — engineered for cylinders bored 0.040" over the standard bore diameter
• Plasma-moly face coating — enhances wear resistance and promotes rapid ring seating
• Barrel-faced compression rings — provide more efficient compression and reduced blow-by
• CNC-controlled gap chamfer — optimizes compression seal and minimizes combustion gas leakage
• Reverse-twist intermediate rings — improve groove side sealing for better oil control
• CP-20 oil ring assembly — features a 20-degree ear angle for maximum side sealing against the cylinder wall
• Chemical-polished oil ring expander — promotes enhanced oil drain-back and reduces oil consumption
• Pre-lapped finish — seats immediately, reducing or eliminating break-in time
• Manufactured to OE specifications for dependable, long-term performance

MAHLE piston rings are trusted by professional engine builders and OEM manufacturers worldwide. The 42086CP.040 set delivers the precision engineering and advanced materials needed for a successful engine rebuild, making it a top choice for both professional shops and experienced DIY builders.