SECTION
GENERAL
DESCRIPTION AND SYSTEM
OPERATION
Cylinder Head and
Valve Train
The cylinder head is made of cast aluminum alloy
for better strength in hardness with lightweight, and camshaft
and rocker arm shaft arranged in-line support.
The combustion chambers are formed into
the manifold combustion chambers with increased squish parts for
better combustion efficiency and its intake and exhaust parts
are installed in the cross flow arrangement. The rocker arm
operates in seesaw motion to close and open the intake and
exhaust valves with camshaft by turning the rocker arm shaft of
each intake and exhaust part.
Engine Block
As the
largest part of the engine components. the block has all the
necessary parts attached to outer surface of it.
On the inside surface of block, there
are bore surfaces by horning, which are cylinders, and on the
periphery of the cylinders, there are the passages to prevent
the over-heated and to lubricate the engine
block.
Crankshaft
The crankshaft is to convert the
rectilinear motion into the rotation motion through the
connecting rod which transmits the power generated by
combustion.
On the one side of
it, oil pump, crankshaft pulley and timing belt pulley are
attached, and oil seal housing and flywheel are on the other
side.
A special steel of high
grade cast iron is used for the material to stand the bending
load and distortion. The material of the main bearing is
aluminum alloy. The split thrust bearings are inserted in the
journal bearing part.
Connecting Rod
The
connecting rods are made of forged steel, and its section is
typed "Ι" with its big end connected to crankshaft and its small
end to piston pin to transmit the power.
The big end is detachable, and its upper and lower
parts are fastened by bolting after the metal bearings are
inserted.
Piston, Piston Ring and Piston Pin
Piston
The piston is of the open skirt type and its crown
is exposed in the combustion chamber to generate power. Its land
and skirt parts are made of coat aluminum alloy which is light
and has excellent heat conductivity in order to meet its
continuous and high speed reciprocation
movement.
Piston Ring
It is composed of two compression rings
and one oil ring and installed between the grooves of the piston
to make the high speed reciprocating movement maintaining a
remarkable air tightness as well as cylinders. It is a critical
parts to affect the compression pressure, oil consumption,
compression, blow by pressure and engine
performance.
Piston Pin
The pin is not fixed to the piston or
connecting rod and its both ends are assembled by the circlip in
the full floating type. The pin is used to transmit the power
from the crown part of piston to connecting
rod.
Timing Belt and Pulley
The
timing belt connects the camshaft timing pulley and the
crankshaft timing pulley. The timing belt coordinates the
crankshaft and the camshaft and keeps them synchronized. The
timing belt also turns the coolant pump. The timing belt and the
pulleys are toothed so that there is no slippage between them.
There is a tension pulley that maintains the correct timing belt
tension. The timing belt is made of a tough reinforced rubber
similar to that used on the serpentine drive belt. The timing
belt requires no lubrication.
Engine Mount
This is
to absorb or reduce the engine vibration and impact from the
wheeled road. Engine mount is attached to the engine-front side,
the engine-right side and the engine-rear side and one transaxle
mount is attached to the transaxle side.
Exhaust Gas
Recirculation Valve
The exhaust gas recirculation (EGR)
system is used tolower oxides of nitrogen (NOX) emission levels
causedby high combustion temperatures. The main element ofthe
system is the EGR valve which is operated electrically by the
ECM.
The EGR valve feeds small
amounts of exhaust gas intothe intake manifold to decrease the
combustion temperature.The amount of exhaust gas recirculated is
controlledby variations in electrical signal and exhaust
backpressure. If too much exhaust gas enters, combustionwill not
take place. For this reason, very little exhaustgas is allowed
to pass through the valve, especially atidle.
The EGR valve is controlled precisely by
ECM according to various operating condition of the
engine.