MAHLE 51669CP.040 Original Premium Plasma-Moly Engine Piston Ring Set - .040 Over

The MAHLE 51669CP.040 is a Premium Plasma-Moly Piston Ring Set machined to .040-inch oversize bore dimensions. Part of MAHLE's Original Premium CP-series line, this set delivers OE-level sealing performance and is engineered for professional engine rebuilds requiring precise tolerances and long-term durability.

Key Features:

• Plasma-Moly Top Compression Ring: Hard-wearing molybdenum coating on the barrel-faced contact area provides efficient compression sealing and extended wear life
• CNC-Controlled Gap Chamfer: Precision-machined ring gaps optimize compression retention and minimize combustion blow-by
• Reverse-Twist Intermediate Ring: Second ring uses a reverse twist design for superior groove side sealing, with taper race machining to enhance cylinder wall contact
• CP-20 Oil Control Ring Assembly: Features an exclusive 20-degree ear angle for best-in-class side sealing against the cylinder wall
• Pre-Lapped Finish: Rings are pre-lapped at the factory to seat immediately, virtually eliminating extended engine break-in time
• .040-Inch Oversize: Designed for bores that have been machined .040 inches over the standard bore diameter
• Optimized Ring Tension: Ring materials, coatings, and tension are balanced for reduced friction and extended service life

MAHLE is the world's largest manufacturer of piston rings, with deep OE engineering expertise built into every aftermarket part. The 51669CP.040 is an installer-friendly solution trusted by professional engine builders for precision, durability, and reliable sealing performance.