Mahle Rings Plasma Moly Steel Top Comp Ring 4.395in x .0625in .190in RW Ring Set (48 Qty Bulk Pack)

When you're rebuilding an engine, especially for a performance application or a heavy-duty workhorse, the piston rings are critical for sealing the combustion chamber and managing oil. What you get in this Mahle OE set is a bulk pack of 48 top compression rings, each measuring 4.395 inches in bore diameter, with a 0.0625-inch thickness and a 0.190-inch ring depth. These are the primary sealing rings, designed to handle the intense pressure and heat inside the cylinder.

Mahle uses plasma-moly steel for these top rings, a well-known material choice for its durability and resistance to wear, especially under demanding conditions. The plasma-moly coating is applied to create a hard, low-friction surface that helps the ring seat properly against the cylinder wall and resist scuffing. This is important because a good seal means better compression, more efficient combustion, and less oil getting past the rings into the combustion chamber. The 4.395-inch bore size is specific, so make sure it matches your pistons and cylinder block dimensions. This bulk pack is ideal for shops or builders who work on multiple engines of the same specification.

It's important to note that these rings are not CARB approved and cannot be shipped to California. Always refer to your specific engine's service manual for proper installation procedures and ring gap specifications, as these can vary based on the application and intended use.