Mahle MS 4.030in+.005in .043in .043in 3.0mm File Fit Rings

This is a Mahle MS piston ring set, designed for engine rebuilds where precise fitment is key. These rings are file-fit, meaning you'll need to adjust the end gap yourself to match your specific cylinder bore. This allows for a custom fit, which is important for optimal sealing and performance in a freshly bored or honed engine. The set includes rings with dimensions of .043 inches for the top and second rings, and a 3.0mm ring for the oil control. They are also specified as +.005 inches, indicating they are intended for use with a bore that has been machined to that size, or for a slight adjustment during installation.

Mahle is a well-known name in engine components, and this set reflects their focus on providing parts for engine overhauls. The low tension design of these rings can help reduce friction, which is beneficial for engine efficiency and longevity. Because they are file-fit, these rings are best suited for experienced engine builders or mechanics who are comfortable with the process of measuring and filing piston ring end gaps to achieve the correct clearance for your engine's bore. This ensures a solid seal between the piston and cylinder wall, preventing blow-by and maintaining compression.

Keep in mind that these rings are not CARB approved and cannot be shipped to California. Always refer to your engine's specific service manual for detailed instructions on measuring and fitting piston rings to ensure a successful rebuild.