MAHLE 3150139.025 Plasma-Moly Piston Ring Set Bore - 4.025

The MAHLE 3150139.025 is a high-performance plasma-moly piston ring set engineered for demanding street, racing, and marine applications. This file-fit ring set features a 4.025" bore size (+.025" oversize) with ring widths of 1/16", 1/16", and 3.0mm, designed to deliver superior sealing and durability in high-output engines.

Advanced Ring Technology:

• Plasma-moly coated ductile iron barrel-faced top ring for instant break-in and consistent cylinder wall contact
• Napier THG (Tapered Hook Groove) second compression ring provides superior oil control and improved combustion gas management
• CP-20 three-piece oil control ring with exclusive 20-degree ear angle for optimal cylinder wall sealing
• Carbon steel construction with standard tension design
• File-fit design allows precise end gap adjustment for your specific application

Performance Benefits:

• Engineered to operate at higher RPM, compression ratios, and temperatures
• Minimizes friction for improved horsepower output
• Enhanced wear resistance under extreme operating conditions
• Superior sealing reduces blow-by and maintains compression
• Suitable for street performance, racing, and marine engine builds

MAHLE performance piston rings are developed using advanced computer simulation and testing to provide the most technically advanced ring sets available. Each ring set includes enough rings for one complete engine rebuild. The barrel-faced top ring maintains contact with the cylinder wall as the piston rocks at TDC and BDC, while the hook groove second ring scrapes oil and creates a reservoir on each downstroke for improved lubrication.