What are the two types of cylinder liners?
2 Answers
Cylinder liners are divided into dry cylinder liners and wet cylinder liners, with the distinction primarily based on whether they come into contact with coolant. Generally, wet cylinder liners have a wall thickness of 5 to 8 mm, while dry cylinder liners have a wall thickness of 1 to 3 mm. Dry cylinder liners are commonly used in gasoline engines, and some low-horsepower diesel engines also employ dry cylinder liners. Wet cylinder liners are used in diesel engines. A cylinder liner is a cylindrical component placed within the cylinder bore of the engine block, secured at the top by the cylinder head, with the piston performing reciprocating motion inside its bore. The outer surface is cooled by circulating water. The inner surface of the cylinder liner is directly exposed to high-temperature, high-pressure combustion gases and continuously undergoes high-speed sliding friction with the piston rings and piston skirt.
When I previously researched engines, I paid special attention to cylinder liners, which commonly come in two types: dry and wet. A dry cylinder liner is like a thin metal sleeve pressed directly into the engine block, with no contact with coolant on the outside. It has a compact structure but poorer heat dissipation. Wet liners, on the other hand, have their outer walls directly immersed in coolant, with thicker sleeve walls and rubber sealing rings to prevent leaks. Mechanics dread wet liner leaks the most, as they require disassembling the engine to replace the seals. While dry liners save space, repairing them after wear involves re-boring the entire block, which can be more costly. Nowadays, many high-performance engines use dry liners, while ordinary family cars mostly use wet liners.
