Mahle Rings Performance Steel Napier THM-13 4.175 x .1.5MM .150RW Plain Ring Set

These Mahle OE piston rings feature a 4.175 inch bore size and a steel Napier design for the top ring. The Napier hook shape on the top ring helps to scrape oil from the cylinder wall, improving lubrication and reducing oil consumption. This set is designed for performance applications, offering a solid option for engine builds where reliable ring seal is critical.

Constructed from durable steel, these rings are built to withstand the demands of an engine. The specific ring groove dimensions are 1.5mm for the top and second rings, with a 0.150 inch ring width for the oil control ring. This precise sizing ensures a proper fit within the piston grooves, contributing to an effective seal between the piston and cylinder wall. Proper ring seal is essential for maintaining compression and preventing blow-by, which directly impacts engine performance and efficiency.