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What is a Great cylinder liner?

It is a cylinder liner that is fitted to the engine block to form the cylinder, and is one critical function part that forms the engine interior.

cylinder liner
cylinder liner

A cylinder liner wall in an engine is under high temperature and high pressure, with the piston and piston rings sliding at high speeds. In particular, since longer service life is required of engines for trucks and buses, cast iron cylinders that have excellent wear-resistant properties are only used for cylinder parts.

Also, with the recent trend of lighter engines, materials for engine blocks have been shifting from cast iron to aluminum alloys. However, as the sliding surface for the inner cylinder, the direct sliding motion of aluminium alloys has drawbacks in deformation during operation and wear-resistance. For that reason, cast iron cylinder liners are used in most cases.

3 functions of  Cylinder Liner

Function 1 Form the sliding surface of cylinder liner

Tightly holds when the valve is seated, prevents compressed gas or combustion gas leaking into the manifold from between the valve and Valve Seat.

-High burn resistance

-Low self-friction

-Low friction with the piston ring

-Low lubricating oil consumption

Function 2 Heat conduction of cylinder liner

Reduces vale and cylinder head friction at the same time.

Function 3 Keep airtightness of cylinder liner

Prevent compressed gas and combustion gas leaking out. The liner should not be prone to deformation due to the high pressure/high temperature inside the cylinder.

The engine’s cylinder wall is high temperature/high pressure, and the piston ring/piston is sliding at high speed, and particularly with truck/bus engines a long-life is demanded, so we use highly friction resistant casting material Cylinder Liners only for cylinders. Also, in recent years, to make engines light-weight, engine blocks are changing from casting to aluminum alloys, however, aluminum alloys suffer deformation and friction during direct sliding when used for the cylinder inner circumference, therefore, the aluminum die cast block is mainly used where the Cylinder Liner is cast-in.

Technical Data of cylinder liner

Material: Material being selected of quality casted closed granuals inspected cast iron holding perfect hardness, machined, tensile strength and wear resistance also it is prepared with help of vanadium, Nickel, Molybdenum and chromium copper.

“Spark” cylinders prepared for easy in fitment to run smooth engine for lowest fuel consumption, from standard specified graded cast iron composites with

 

Total Carbon : 3 to 3.5%

Sulphar : 0.12%

Phosphorous : 0.2% to 0.6%

Manganese : 0.6 to 1.2%

SiliconChrome : 1.8 to 2.5%, 03.0 Max

 

 

The cylinder liner or sleeves are of two types:

-Dry liners.

-Wet liners.

  1. Dry Liners.

Dry liners are made in the shape of a barrel having a flange at the top. The flange keeps the liner in position in the cylinder block.

The liner fits accurately in the cylinder. The perfect contact of the liner with the cylinder block is necessary for the effective cooling of the liner.

Also, the gas pressure, piston thrust and impact loading during combustion are resisted by the combined thickness of the liner and the cylinder.

Therefore, dry liners are thinner, having wall thickness varying from 1.5 mm to 3 mm and are used mostly for reconditioning worn liners.

 

The dry liners are not in direct contact with cooling water.

 

  1. Wet Liners.

A wet liner is so-called because the cooling water comes in contact with the liner. This liner is provided with a flange at the top, which fits into the groove made in the cylinder block.

To stop leakage of cooling water in the crankcase, the lower end of the wet liner is sealed with the help of sealing rings or packing rings.

As the wet liner has to withstand gas pressure, thrust and impact loading, the wall thickness of the liner is increased and is made more than that of the dry liner.

Generally, the wall thickness of the wet liner ranges from 3 mm to 6 mm. The outside of the liner is coated with aluminum so that it is protected from rust.

The wet liner is better cooled than the dry liner. It is easily removable when it is worn-out or damaged.

 

Comparison of Dry and Wet Liners.

  1. A wet liner can be easily replaced whereas a dry liner requires special tools because it is tight-fitted in the cylinder block.
  2. A wet liner is properly cooled as it comes in direct contact with the cooling water, whereas a dry liner does not come in direct contact with the cooling water. Hence, the working temperature of a dry liner is more than a wet liner.
  3. A wet liner needs leak-proof joints so that the cooling water does not leak into the crankcase, whereas a dry liner has no such requirement.
  4. A wet liner does not require accurate finishing on the outside, whereas a dry liner needs accurate finishing.
  5. Finishing may be completed in a wet liner before assembly, whereas a dry liner needs finishing after assembly.

If you want high-quality cylinder liners, please contact us LandTop to provide you with high-quality accessories and services.

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