Cylinder liners are precision-honed, tubular components installed within the engine block to create the combustion chamber’s sealing surface. Typically utilized in heavy-duty and high-performance engines, they provide a durable, replaceable wear surface for piston travel. Liners are constructed from cast iron, steel, or coated alloys, optimized for heat dissipation and minimizing friction. Wet liners are directly cooled by engine coolant, while dry liners rely on the block for thermal management. Precise dimensional control and surface finish are critical for maintaining compression and preventing oil consumption.