MAHLE 3150049-045 Plasma-Moly Performance Piston Ring Set Bore File Fit - 4.045

The MAHLE 3150049-045 is a Plasma-Moly Performance Piston Ring Set designed for 8-cylinder engines with a 4.045" bore (+.045" oversize). Built from SAE 9254 carbon steel with a proprietary plasma-moly face coating, this file-fit, low-tension ring set delivers the tensile strength, hardness, and fatigue resistance demanded by high-output and high-RPM performance engines.

Key Features:

• Bore Size: 4.045" (+.045" oversize)
• Ring Widths: 1/16" top compression, 1/16" second compression, 3.0mm oil control
• Fit Type: File Fit — allows custom end-gap setting for performance builds
• Tension: Low Tension for reduced friction and improved power output
• Material: SAE 9254 carbon steel construction with plasma-moly face coating
• Top Ring: Barrel-faced design for rapid break-in and consistent cylinder wall contact through piston rock at TDC and BDC
• Second Ring: Napier THG (tapered hook groove) design provides superior oil control, improved combustion gas management, and enhanced top ring stability
• Oil Control Ring: CP-20 design with exclusive 20-degree ear angle for maximum cylinder wall sealing
• Recommended for street, racing, and marine performance applications

The plasma-moly face coating extends ring life, eliminates ring breakage, reduces side wear, and minimizes groove pound-out. The steel ring's smaller cross-section lowers ring mass, improving the ring's ability to tolerate inertial forces and conform to cylinder bore distortion in high-output engines. The top ring groove can also be positioned closer to the top of the piston, reducing crevice volume and unburned fuel emissions. Set covers 8 cylinders.