What is the Napier hook design?

The Napier hook design is a feature in the top piston ring that helps prevent the ring from sticking in its groove. This is particularly beneficial in high-heat and high-load situations, aiding in maintaining a proper seal and reducing oil consumption.

What are the specific dimensions for this ring set?

This ring set is for pistons with a 4.145-inch bore. The top and second ring grooves are 1.5mm, and the oil control ring rail is 0.150 inches wide.

Can this product be shipped to California?

No, this product is not CARB approved and cannot be shipped to California due to emissions regulations.

Mahle OE Piston Rings 3021272

Name: Mahle Rings Performance Steel Napier THM-13 4.145 x .1.5MM .150RW Plain Ring Set
Brand: Mahle OE
SKU: mahle-oe-mahle-rings-performance-steel-napier-thm-13-4-145-x-1-5mm-150rw-plain-r-t14-47681
Price: 58.02 USD
Availability: BackOrder

Mahle Rings Performance Steel Napier THM-13 4.145 x .1.5MM .150RW Plain Ring Set

$58.02

On Backorder

Order now to reserve yours — we'll ship as soon as stock arrives. Full refund if we're unable to fulfill.

Mahle OE steel Napier piston rings. Part# 3021272. Direct fit.

Key Features

Mahle OE steel Napier piston ring set.
Designed for pistons with a 4.145-inch bore.
Top ring groove: 1.5mm.
Second ring groove: 1.5mm.
Oil control ring rail width: 0.150 inches.
Features a Napier hook design for improved oil control and anti-sticking.

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Product Details

Mahle is a well-known name in the automotive world, especially for their engine components. This particular set of piston rings, the THM-13, is designed for performance applications and features a steel Napier hook design. These rings are built to fit pistons with a 4.145-inch bore and utilize specific ring groove dimensions: 1.5mm for the top ring, 1.5mm for the second ring, and a 0.150-inch width for the oil control ring rail.

The Napier hook design in the top ring is a notable feature. It helps to prevent the ring from sticking in the groove, especially under high heat and load conditions, which is crucial for maintaining a good seal and preventing oil from entering the combustion chamber. This design contributes to improved oil control and can help reduce blow-by, leading to more consistent engine performance. The steel construction offers good durability for demanding use.

Please be aware that this ring set is not CARB approved and cannot be shipped to California. Always refer to the manufacturer's installation instructions for proper fitment and assembly procedures.