Mahle MS 4.040in+.005in .043in .043in 3.0mm File Fit Rings

These Mahle file fit piston rings are built to a specific size: 4.040 inches with an additional .005 inch clearance, and feature a 3.0mm top ring, a 3.0mm second ring, and a 1.5mm oil ring. This precise sizing is crucial for custom engine builds where standard rings might not offer the exact fit needed for optimal performance and sealing. The file-fit design means you can adjust the end gap yourself, ensuring a perfect match for your specific cylinder bore. This level of customization is often necessary when working with modified engines or when rebuilding with non-standard piston and bore dimensions.

Mahle is a well-known name in engine components, and this ring set reflects their focus on precision. The low-tension design helps reduce friction, which can lead to improved engine efficiency and a bit more power. Because these are file-fit, they require careful installation to set the correct end gap for your application. It's important to have the right tools and a good understanding of engine building principles when working with file-fit rings to ensure they perform as intended and last.

Keep in mind that these rings are not CARB approved and cannot be shipped to California. If you're building a performance engine or a custom setup where precise ring gap is a priority, this Mahle set offers the adjustability and quality you're looking for.