Mahle Rings Perf Plasma Steel Top Ring 4.020in x 1.0MM .143in RW HVOF Moly Ring Set (48 Qty Bulk Pk)

When you're rebuilding the top end of an engine, getting the piston rings right is critical for sealing combustion pressure and controlling oil. This set from Mahle OE features plasma-moly coated top rings, a popular choice for performance builds where durability and good sealing are key. The plasma-moly coating helps reduce friction and wear, especially during the break-in period, and it holds up well under higher cylinder pressures.

These rings are made from steel, which offers good strength and resilience. The top ring has a 1.0mm thickness and is designed for a 4.020-inch bore size. The HVOF (High Velocity Oxygen Fuel) application process for the moly coating creates a dense, well-bonded layer that resists scuffing and provides excellent wear characteristics. This bulk pack contains 48 rings, making it suitable for engine builders or shops working on multiple engines.

Proper installation is key for these rings to perform as intended. Ensure you follow the manufacturer's guidelines for ring gap, tension, and seating during the break-in process. This set is designed for performance applications, so pay close attention to the specific engine build requirements.