Mahle MS 4.125in+ .005in 1.5 1.5 3.0 mm File Fit Rings

This is a Mahle MS 4.125 inch plus .005 inch file fit piston ring set, part number 4130MS-15. These rings are designed for engine rebuilds where precise control over the piston ring gap is crucial for optimal performance and sealing. The file-fit design means you'll adjust the end gap yourself during installation to perfectly match your specific cylinder bore, ensuring a solid seal.

Mahle is a well-known name in engine components, and this set features a common ring configuration: two compression rings measuring 1.5mm each, followed by a 3.0mm oil control ring. The +.005 inch sizing indicates these are intended for a bore that is slightly larger than standard, or for applications where a specific piston-to-wall clearance is desired. This level of adjustability is important for achieving good compression and preventing oil blow-by, especially in performance or heavily modified engines.

Remember that these rings are not CARB approved and cannot be shipped to California. Proper installation requires careful measurement and filing to achieve the correct ring gap for your engine's bore size.