In two strokes Compression ignition engine a cycle is
completed in two stroke of a piston or one complete
of a crankshaft. In this engine the suction stroke and
exhaust strokes are eliminated and ports are used instead of
valves. The fuel used in this type of engine is diesel.
The major components of a four stroke compression Ignition
It is a cylindrical vessel in which a piston makes up and
It is a cylindrical component making up and down movement in
It is the portion above the cylinder in which the combustion
of the Fuel-air mixture takes place.
The inlet port allows the fresh fuel-air mixture to enter
the combustion chamber and the exhaust port discharges the
products of combustion.
It is a shaft which converts the reciprocating motion of
piston into the rotary motion.
The connecting rod connects the Piston with the crankshaft.
The cam shaft controls the opening and closing of inlet and
It is located at the cylinder head. It is used to admit the
fuel into the combustion chamber.
piston moves from bottom dead centre to top dead centre, the
fresh air enters the crank chamber through the valve. The
air enters due to the pressure difference between the crank
chamber and outer atmosphere. At the same time the air above
the piton is compressed.
Fuel with the help of fuel injector is admitted
into the combustion chamber at the end of stroke. The
combustion takes place as the temperature of the fuel-air
mixture reaches its ignition point. Due to the explosion of
the gases, the piston moves downward. When the piston moves
downwards the valve closes and the fresh air inside the
crank chamber is compressed. When the piston is at the
bottom dead centre, the burnt gases escape from the exhaust
same time the transfer port is uncovered and the compressed
air from the crank chamber enters into the combustion
chamber through transfer port. This fresh air is deflected
upwards by a hump provided on the top of the piston. This
fresh air removes the exhaust gases from the combustion
Again the piston moves from bottom dead centre
to top dead centre and the air gets compressed when the both
the Exhaust port and Transfer ports are covered. The cycle