Mahle Rings Performance Napier THM-13 4.185 x .043 .135inRW Plain Ring Set

Mahle is well-known for making reliable engine components, and this set of Performance Napier THM-13 piston rings is no exception. These rings are designed to fit pistons with a 4.185 inch bore, and they feature a specific ring groove size of .043 inches for the top ring and .135 inches for the second ring, with a Napier hook design on the second ring. This setup is often used in performance builds where improved oil control and sealing are important.

The Napier hook on the second ring is a notable design feature. It helps to scrape oil from the cylinder wall as the piston moves down, which can lead to better lubrication for the piston and reduced oil consumption. The precise dimensions ensure a good seal against the cylinder wall, helping to maintain compression and prevent blow-by. This makes them a solid option when you're rebuilding an engine and want dependable performance from your piston rings.