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

File fit rings are designed so you can manually adjust the end gap by filing them down. This allows for a precise fit in custom bore sizes or specific engine builds where standard rings might not offer the optimal gap.

What tools are needed to install file fit piston rings?

Installing file fit rings requires careful measurement and a specialized ring filer tool to ensure the ends are filed accurately and cleanly. You will also need a micrometer or caliper for precise gap measurement.

Can these rings be used in any engine?

These rings are intended for custom engine builds where precise gap control is needed. While they are universal in size, their file fit nature means they are best suited for experienced builders working with specific engine blueprints and custom pistons.

Mahle Piston Ring Set 4255MS-112

Name: Mahle MS 4.250in +.005in 1.0mm 1.0mm 2.0mm File Fit Rings
Brand: Mahle
SKU: mahle-mahle-ms-4-250in-005in-1-0mm-1-0mm-2-0mm-file-fit-rings-t14-29744
Price: 257.48 USD
Availability: BackOrder

Mahle MS 4.250in +.005in 1.0mm 1.0mm 2.0mm File Fit Rings

$257.48

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 4.250in +.005in file fit piston ring set. For custom engine builds needing precise ring gap adjustment.

Key Features

This product is a Mahle MS file fit piston ring set.
The rings are sized at 4.250 inches with a +.005 inch allowance for file fitting.
The set includes a 1.0mm top ring, a 1.0mm second ring, and a 2.0mm oil control ring.
These are standard tension rings.
Designed for custom engine builds requiring precise ring gap adjustment.
Not CARB approved and cannot be shipped to California.

⚠️ 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

This set includes Mahle MS file fit piston rings, sized at 4.250 inches with a +.005 inch allowance for file fitting. The ring dimensions are 1.0mm for the top ring, 1.0mm for the second ring, and 2.0mm for the oil control ring. These are standard tension rings designed for custom engine builds where precise control over the piston ring gap is essential for optimal performance and sealing.

Mahle is a well-known name in engine components, and this ring set reflects their focus on precision. The file fit design means you can carefully adjust the end gap to match your specific cylinder bore and application, which is crucial for preventing blow-by and ensuring good compression, especially in modified or performance engines. This level of adjustability is often needed when working with custom pistons or non-standard bore sizes. The standard tension is suitable for a wide range of applications, providing a solid seal without excessive cylinder wall pressure.

Because these are file fit rings, they are intended for experienced engine builders or those working with a detailed engine blueprint. You'll need the proper tools to safely and accurately file the ring ends to achieve the correct gap. Remember, these rings are not CARB approved and cannot be shipped to California.