Mahle Rings Performance Napier THM-13 4.190 x .043 .135in RW Plain Ring Set (48 Qty Bulk Pack)

The 4.190-inch bore size and specific ring dimensions of .043 inches for the top ring and .135 inches for the oil ring are key to the performance of this Mahle OE Piston Ring Set. These dimensions are designed to work with specific piston profiles, ensuring a tight seal within the cylinder bore. The Napier-style top ring is a notable design choice, helping to reduce oil consumption and improve ring flutter at higher RPMs by allowing oil to drain back into the crankcase more effectively.

This bulk pack contains 48 sets of rings, making it a solid option for engine builders or shops working on multiple engines with the same bore size. Mahle OE is a well-known name in engine components, and these rings are built to meet the demands of performance applications where a reliable seal and efficient oil control are critical. The plain finish on the rings is standard for many performance applications, allowing for proper seating and break-in with the cylinder wall.