Mahle MS 4.615in+.005in .043in .043in 3.0mm Steel STD Tension File Fit Rings

When you're rebuilding the top end of an engine, getting the piston rings seated just right is critical for sealing and performance. This set from Mahle is designed for that precise job, offering a standard tension and a file-fit design that lets you achieve the perfect gap for your specific cylinder bore. They're made from steel, which is a strong material for this application.

The rings in this set measure .043 inches for the top two rings and 3.0mm for the oil ring. They are also specified as +.005 inch oversize, meaning they are intended for a cylinder bore that has been honed out by five-thousandths of an inch. The 'file fit' aspect means you'll need to file the end gap to match your bore size, a common practice for performance or custom engine builds where exact tolerances are key. This ensures a solid seal between the piston and the cylinder wall, which is essential for good compression and preventing blow-by.

Because these are file-fit rings, they require careful measurement and adjustment of the end gap to match your engine's specific cylinder bore. Always refer to your engine's service manual for the correct procedure and specifications when installing file-fit piston rings. Please note that these rings are not CARB approved and cannot be shipped to California.