MAHLE 51724CP.020 Standard Piston Ring Set Oversize - 0.020in

The MAHLE 51724CP.020 is a standard piston ring set ground to a +0.020-inch oversize bore, engineered as part of MAHLE's Original CP-series lineup. MAHLE is the world's largest manufacturer of piston rings, and the Original line carries decades of OE-level engineering directly into the aftermarket rebuild market.

These rings are pre-lapped at the factory to seat immediately upon installation, virtually eliminating traditional break-in time. Ring materials, coatings, and tension levels are all optimized for reduced friction and extended service life in each specific application.

Key Features:

• +0.020-inch oversize bore sizing for engines requiring a first overbore
• Compression rings feature a barrel-faced contact area for more efficient sealing and reduced blowby
• CNC-controlled gap chamfer on compression rings optimizes compression and minimizes combustion gas loss
• Intermediate (second) rings use a reverse twist design for superior groove side sealing, with taper race machining to enhance wall contact
• CP-20 oil control ring assembly with an exclusive 20-degree ear angle for maximum side seal against the cylinder wall
• Special chemical polish on the oil ring expander promotes enhanced oil drainback
• High tensile strength and high yield strength cast iron construction with excellent hardness and low ring mass
• Engineered for stress resistance, minimal groove pound-out, long service life, and good blowby control

The MAHLE Original piston ring set (formerly Perfect Circle) is trusted by professional engine builders and automotive technicians for over 100 years. Whether performing a standard engine overhaul or a precision rebuild, the 51724CP.020 delivers OE-quality fit and durability in an installer-friendly package.