Mahle Rings Steel Napier THM-13 4.610 Bore x 1.0MM .136 RW Plain Ring Set (48 Qty Bulk Pack)

Mahle is a well-known name in the automotive industry, particularly for their expertise in engine components. This bulk pack of steel Napier piston rings, part number 3021191B, is designed for engine rebuilding projects where precision and durability are key. These rings are built to fit a 4.610 inch bore and feature a 1.0mm thickness with a .136 inch ring width, utilizing a Napier hook design for improved oil control and reduced friction.

The Napier hook design is a notable feature in these rings. Unlike conventional rings, the Napier hook has a stepped profile on the back of the ring. This step helps to scrape oil down the cylinder wall more effectively during the piston's downstroke, which can lead to improved oil consumption control and reduced blow-by. The steel construction offers good wear resistance and strength, making these rings a solid choice for performance or heavy-duty applications where standard cast iron rings might not hold up as well. This is a bulk pack containing 48 sets of rings, making it suitable for shops or builders working on multiple engines.

When rebuilding an engine, ensuring proper ring seal is critical for compression, power, and oil control. These Mahle rings are intended to provide a reliable seal within the specified bore size. It's important to note that these rings are not CARB approved and cannot be shipped to California. Always refer to your engine's specific service manual for installation procedures and recommended clearances.