MAHLE 42171.020 Engine Piston Ring Set Oversize - 020

The MAHLE 42171.020 is a premium engine piston ring set featuring a .020-inch oversize bore dimension, designed for engine rebuilds where cylinders have been bored or honed beyond standard size. As an OEM-level component from MAHLE Original — the world's largest piston ring manufacturer — this set is engineered to restore combustion sealing, oil control, and compression to factory specifications.

Key Features:

• .020 oversize bore sizing for use in bored or honed engine rebuilds
• Pre-lapped rings seat immediately upon startup, virtually eliminating traditional break-in requirements
• Ring materials, coatings, and tension levels optimized for reduced friction and extended service life
• Compression rings feature a barrel-faced contact area for efficient sealing and a CNC-controlled gap chamfer to minimize blow-by
• Intermediate rings use a reverse twist design for enhanced groove side sealing with taper race machining for improved contact
• CP-20 oil ring assemblies with a 20-degree ear angle provide superior cylinder wall side sealing
• Oil ring expander features a special chemical polish for enhanced oil drain-back performance
• Meets or exceeds original equipment manufacturer (OEM) specifications

MAHLE Original piston rings are trusted by professional engine builders for their installer-friendly design and technically advanced construction. The complete ring set is ideal for full engine rebuilds requiring proper compression restoration and long-term oil control.