2236361 Ring-Piston Oil Fits Caterpillar ModelsOne New Aftermarket Replacement Piston Oil Ring for Caterpillar (Cat) Engines This piston oil ring (ring piston oil) is an engine internal component used in Caterpillar's large displacement 3500 series engines. It seats in the oil control groove of the piston to regulate oil film on the cylinder wall, preventing oil consumption and maintaining compression integrity. This part fits a wide range of Caterpillar construction, mining, power generation, and