What does 'file fit' mean for these piston rings?

File fit means the ends of the piston rings are not pre-gapped. You will need to use a specialized ring filer tool to carefully file down the ends of each ring to achieve the precise gap specified for your engine's bore and intended use.

What are the dimensions of these rings?

This set includes a 1.5mm top ring, a 1.5mm second ring, and a 3.0mm oil ring. The overall diameter of the rings is 4.390 inches, with an extra 0.005 inches of clearance for custom fitting.

Can these rings be shipped to California?

No, these rings are not CARB approved and cannot be shipped to California due to emissions regulations.

Mahle Piston Rings 4.390in+ .005in 1.5 1.5 3.0 mm File Fit R

Name: Mahle MS 4.390in+ .005in 1.5 1.5 3.0 mm File Fit Rings
Brand: Mahle
SKU: mahle-mahle-ms-4-390in-005in-1-5-1-5-3-0-mm-file-fit-rings-t14-29809
Price: 179.36 USD
Availability: BackOrder

Mahle MS 4.390in+ .005in 1.5 1.5 3.0 mm File Fit Rings

$179.36

On Backorder

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

Mahle MS 4.390in+ .005in 1.5 1.5 3.0 mm file fit piston ring set. These rings are designed for custom engine builds where precise fitment is key.

Key Features

This piston ring set measures 4.390 inches in diameter with an additional 0.005 inches of clearance.
The file-fit design requires you to adjust the ring end gap for your specific application.
Features a 1.5mm top ring, a 1.5mm second ring, and a 3.0mm oil ring.
This is a universal fitment ring set, intended for custom engine builds.
Mahle is a popular brand for engine components.

This is a universal fitment ring set intended for custom engine builds. Please verify compatibility with your specific engine requirements.

⚠️ CA WARNING: This product can expose you to chemicals known to the State of California to cause cancer and/or birth defects or other reproductive harm. Learn more

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Product Details

These Mahle file-fit piston rings are precisely 4.390 inches in diameter, with an additional 0.005 inches of clearance built in. This extra bit of room means you'll need to file the ends of the rings to achieve the exact gap required for your specific engine build. This level of adjustability is crucial for high-performance or custom engine work where optimal sealing and compression are paramount. The ring set features a common 1.5mm top ring, a 1.5mm second ring, and a 3.0mm oil ring, a popular configuration for many performance applications.

Mahle is a well-known name in engine components, and this set reflects their focus on precision. The file-fit design allows experienced builders to dial in the ring-to-cylinder wall seal, which can significantly impact engine performance and longevity. Proper gapping helps prevent blow-by and ensures the rings can effectively control oil consumption. If you're rebuilding an engine and need to achieve a perfect seal, especially in a non-standard bore size, these Mahle rings offer the adjustability you need.

Keep in mind that these rings are not CARB approved and cannot be shipped to California. Also, be aware of the Prop 65 warning associated with this product.