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CHAPTER TEREE:
STRUCTURAL CHARCAITERISTICS AND
ADDEMBLY REQUIREMENTS OF ENGINE
3.1 CYLINDERHEAD ASSEMBLY
Cylinder head is made of high strength aluminum alloy. The shape of combustion chamber is
hemispherical. Intake and exhaust runners are distributed on two sides. The overhead camshaft of value
train has very good suitability by three bearing in the cylinder head and driven by timing chain. There are
the advantages of being stable in transmission, compact in structure and low noise.
Rocker arm is made of high strength aluminum alloy with inlaid alloy resists very high
temperature. A sealing unit is used for value stem so that engine oil can not enter combustion
chamber phase angle between the No.1 cylinder and the No.2 cylinder is 360 degrees crank angle.
A. Point for installing timing chain
Rotate crankshaft to TDC
position before installing timing chain.
Then align marks on timing sprocket
of crankshaft and camshaft sprocket
with the white and bright chain
element respectively. Now the
locating pin in camshaft should be
right at the top position (refer to
fig.3-1)
B. Locating TDC
Rotate crankshaft to make
pistons in two cylinders go to their
TDC positions in turn. Now the
center mark on boss of crankshaft
pulley should align with the boss of
timing chain cover. Remove cylinder
head cover if the locating pin in
camshaft sprocket is at the position shown in fig.3-2. The piston in No.1 cylinder is at the position
of compression stroke. If locating pin is at opposite position the piston in No.2 cylinder is at TDC
position of compression stroke.
