Engine Cylinder Liners
A cylinder liner is a thin, metallic, cylinder-shaped part inserted into an engine block to form the inner wall of the cylinder. In some countries, it is known as a cylinder sleeve. Regardless of the name, it remains one of the most important functional parts of the interior of an engine. During use, cylinder liners are subject to wear and tear from the rubbing action of the piston rings and piston skirt, and must be able to withstand it. This wear is minimized by the application of a thin oil film that coats the walls of the cylinder and a layer of naturally-forming glaze that forms as the engine runs. Cylinder lines are expensive, precisely-manufactured, specialty parts, but their importance and benefits cannot be overstated.
Cylinder liners serve three primary functions: formation of a sliding surface, transfer of heat, and compression gas sealing. The cylinder liner, functioning as the inner wall of the cylinder, forms a sliding surface for the piston rings while retaining lubricant within. The use of a cylinder liner as a sliding surface provides four further benefits: high anti-galling properties, less wear on the cylinder liner itself, less wear on the partner piston ring, and less consumption of lubricant. Additionally, cylinder liners aid in the transfer of heat. Combustion heat is received by the cylinder liner via the piston and piston rings, which transmit heat to the coolant. Finally, cylinder liners offer compression gas sealing properties, preventing compressed and combustion gases from escaping the engine. To achieve this, a cylinder liner must be able to maintain its shape when exposed to high stress and high temperature in the cylinder.
There are three common types of cylinder liners: dry, wet, and finned cylinder liners. Dry cylinder liners are some of the most basic piston protectors. They must be able to withstand extremely high temperatures and protect the cylinder from impurities, so these are constructed of high-grade materials including case iron, ceramic-nickel plating, and more. Compared to wet liners, dry cylinders are much thinner. Additionally, dry cylinder liners do not interact with engine coolant but rather provide a very tight fit with the jacket in the cylinder block, thereby protecting the piston from heat and impurities.
Wet cylinder liners protect the pistons in a much different way than dry liners, but are made from the same hard material. Wet cylinder liners come in direct contact with engine coolant, hence the name ‘wet.’ In some cases, wet cylinder liners are fitted with tiny openings that help disperse heat and impurities. These types of liners are sometimes called water-jacket liners but are still considered a variant of the wet cylinder liner. If the liner is lacking a cooling jacket, one is created through the liner’s interaction with the jacket in the cylinder block.
The final type of cylinder linder, finned cylinder liners, are constructed of the same type of heat-resistant metal as the others. Finned liners are designed specifically for air-cooled engines, and their operation works much like the dry cylinder liner in that the primary cooling medium for the motor is air. These filters derive their name from the tiny fins they are fitted with which allow air to be drawn in with great force around the cylinder to provide further cooling.
At ASAP NSN Hub, owned and operated by ASAP Semiconductor, we can help you find all types of cylinder liners and cylinder block parts and deliver them with short lead times and competitive prices.For a quick and competitive quote, email us at sales@asapnsnhub.com or call us at +1-920-785-6790. Our team of dedicated account managers is standing by and will reach out to you in 15 minutes or less.
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