Cylinder Liner/ Cylinder Sleeve
•A cylinder liner is a cylindrical part to be fitted into an engine
block to form a cylinder. It is one of the most important
functional parts to make up the interior of an engine.
This is called Cylinder liner in Japan, but some countries(or
companies) call this Cylinder sleeve.
•Cylinder sleeves are used in engine blocks to provide a hard-
wearing material for pistons and piston rings.
These are main functions of Cylinder Liners
(1)Formation of sliding surface
MATERIAL FOR CYLINDER LINER
•Current Materials for Cylinder Liner The
current markets usually use is grey cast iron
with lamellar graphite (ASTM Grade 40) with
pearlitic type microstructure. Aluminium
alloy also used. Liner materials were usually
from different alloys of cast iron, such as
phosphorous, titanium and vanadium
C Si Mn S Cr Ni Mo V Cu Al
3.5 1.9 0.73 <0.2 0.23 0.07 0.31 0.015 0.27 <0.01
• The Centrifugal Casting process is used to cast cylinder
• With the help of centrifugal casting process the thickness of
cylinder liner can easily controlled.
• In centrifugal casting, a permanent mold is rotated
continuously about its axis at high speeds (300 to 3000 rpm) as
the molten metal is poured. The molten metal is centrifugally
thrown towards the inside mold wall, where it solidifies after
cooling. The casting is usually a fine-grained casting with a very
fine-grained outer diameter, owing to chilling against the mould
surface. Impurities and inclusions are thrown to the surface of
the inside diameter, which can be machined away.
• Casting machines may be either horizontal or vertical-
axis. Horizontal axis machines are preferred for long, thin
cylinders, vertical machines for rings.
• Most castings are solidified from the outside first. This may be
used to encourage directional solidification of the casting, and
thus give useful metallurgical properties to it.
Features of centrifugal casting
• Castings can be made in almost any length, thickness
• Different wall thicknesses can be produced from the
same size mold.
• Eliminates the need for cores.
• Mechanical properties of centrifugal castings are
• Only cylindrical shapes can be produced with this
• Size limits are up to 3 m (10 feet) diameter and 15 m
(50 feet) length.
• Wall thickness range from 2.5 mm to 125 mm (0.1 -
• Typical parts made by this process are pipes,
boilers, pressure vessels , flywheels, cylinder
liners and other parts that are axi-symmetric.
• It is notably used to cast cylinder
liners and sleeve valves for piston engines,
parts which could not be reliably
STEPS TO MANUFACTURE CYLINDER LINER
STEP 1: MELTING OF METAL
STEP 2: POURING OF MOLTEN METAL
STEP 3: CENTRIFUGAL CASTING
STEP 4: BORING
STEP 5: CNC TURNING
STEP 6: HONING
STEP 7: GRINDING
MELTING OF METAL
Cast iron is melted at 1150 to 1200 °C
in a furnace.
POURING OF METAL IN TO THE CENTRIFUGAL
• Molten metal is carried from furnace through ladle.
• Then the metal is poured in the pouring basin which leads the molten
metal into centrifugal casting machine.
• Molten metal is poured in moving centrifugal die which provides it a
• Some additives are also added during pouring to get defect free
• How much molten metal is poured depends on the desired thickness
• Molten metal should be poured continuously to uniformly distribute
the molten metal over the surface of the mold.
CENTRIFUGAL CASTING OF CYLINDER LINER
• When the metal is poured, As the mold is rotating about
its axis So due to centrifugal force the molten metal is
uniformly distributed over the surface of mold.
• The rotated molds (approx. 900 rpm) forces the molten
metal by centrifugal force towards molds cavity walls.
• There is no need of central core to cast a hollow cylinder
• Due to lighter weigh impurities comes out of molten metal
into the center while heavy weigh molten metal goes on the
mold cavity walls.
• As metal starts solidify and after 5 to 10 min the molds
rotation is stopped.
• After the solidification of metal the casting is removed by
tapping and forcing it out of mold.
• Due to thin wall casting the solidification may starts from
the center hole before the solid metal from the outside
• When the solidification proceeds from both the outer
and inner surfaces, there necessarily will be a certain
amount of shrinkage called center-line shrinkage.
WAYS PREVENT THE CENTER LINE SHRINKAGE
• One way of preventing this shrinkage is to regulate the
rate of pouring in order to keep the inner surface hot
• Another aid is the spraying of an insulating material
which is lighter the cast iron into the central hole over
the inner surface.
• This material minimizes the transfer of heat from the
inner surface and permits the casting to solidify from its
outer surface inward as desired.
• Boring is the process which gives the final look of inner
• We can perform boring operation on vertical machining
center. Which is fully computerized control machine.
• We can also use special purpose boring machine. Which
maintains dimension accuracy, taper and surface finish.
• We can perform outer diameter of liner on CNC
machine, which is computerized control machine, gives
high accuracy in dimensional parameters, surface
roughness parameters and geometrical parameters.
• A main benefit of OD CNC Turing is to minimize cycle
time, repeatability of quality and consistency product.
• Honing is an abrasive machining process that produces
a precision surface on a metal workpiece by scrubbing
an abrasive stone against it along a controlled path.
• Honing is primarily used to improve the geometric form
of a surface, but may also improve the surface texture.
• Honing machines Vertical Plateau Honing Machine,
Horizontal Honing Machine, Hydraulic Vertical Honing
Machine is used for such purposes.
• Grinding is an abrasive machining process that uses
a grinding wheel as the cutting tool.
• Grinding is the process where super surface finish can be
maintained on products.
• We may use two type of grinding process center less
grinding and cylindrical grinding.
• Grinding controls dimensional parameters, surface
parameters and geometrical parameters
• Casting and Forming Processes in Manufacturing by
James S. Campbell, jr.