Mahle MS 4.280in+.005in 1.0mm 1.0mm 2.0mm File Fit Rings

This is a Mahle MS piston ring set, specifically designed for engines that require a 4.280 inch bore with a .005 inch oversize. These rings feature a 1.0mm top ring, a 1.0mm second ring, and a 2.0mm oil control ring, all of which are file-fit style. This means you'll need to carefully file the end gap of each ring to achieve the precise clearance needed for your specific engine build, which is common in performance or custom engine work where exact tolerances are critical.

Mahle is a well-known name in engine components, and this ring set is built to their standards. The file-fit design allows for a custom fit, ensuring optimal sealing between the piston and cylinder wall. This improved seal is crucial for maintaining compression, preventing blow-by, and controlling oil consumption, all of which contribute to a healthy and powerful engine. The different ring thicknesses (1.0mm, 1.0mm, 2.0mm) are chosen to balance sealing performance and oil control for a wide range of applications.

Because these are file-fit rings, they are intended for engine builders who are comfortable with precise measurements and adjustments. They are not a direct bolt-on part and require careful installation to ensure proper function and longevity. Please note that this product is not CARB approved and cannot be shipped to California.