1. External combustion (E.C.) Engine
It is an engine in which combustion of fuel take place outside of the engine. In this
type of engine heat, which is generated by burning of fuel is use to convert the water or
other low boiling temperature fluid into steam. This high pressure steam used to rotate
a turbine. In this engine we can use all solid, liquid and gases fuel. These engines are
generally used in driving locomotive, ships, generation of electric power etc.
Advantages of E.C. engine-
In these engines starting torque is generally high.
Because of external combustion we can use cheaper fuels as well as solid fuel.
They are more flexible compare to internal combustion engines.
2. Internal Combustion (I.C.) Engine
It is an engine in which combustion of fuel take place inside the engine. When the
fuel burns inside the engine cylinder, it generates a high temperature and pressure.
This high pressure force is exerted on the piston (A device which free to moves inside
the cylinder and transmit the pressure force to crank by use of connecting rod), which
used to rotate the wheels of vehicle. In these engines we can use only gases and high
volatile fuel like petrol, diesel. These engines are generally used in automobile
industries, generation of electric power etc.
Advantages of I.C. engine-
It has overall high efficiency over E.C. engine.
These engines are compact and required less space.
Initial cost of I.C. engine is lower than E.C. engine.
This engine easily starts in cold because of it uses high volatile fuel.
Types of I.C. Engine
I.C. engine is widely used in automobile industries so it is also known as automobile
engine. An automobile engine may be classified in many manners. Today I am going to
tell you some important classification of an automobile engine.
According to number of stroke:
1. Two stroke engine
In a two stroke engine a piston moves one time up and down inside the cylinder and
complete one crankshaft revolution during single time of fuel burn. This type of engine
has high torque compare to four stroke engine. These are generally used in scooters,
pumping sets etc.
2. Four stroke engine
In a four stroke engine piston moves two times up and down inside the cylinder and
complete two crankshaft revolutions during single time of fuel burn. This type of
engines has high average compare to two stroke engine. These are generally used in
bikes, cars, truck etc.
According to design of engine:
1. Reciprocating engine (piston engine)
In reciprocating engine the pressure force generate by combustion of fuel exerted
on the piston (A device which free to move in reciprocation inside the cylinder). So the
piston starts reciprocating motion (too and fro motion). This reciprocating motion
converts into rotary motion by use of crank shaft. So the crank shaft starts to rotate
and rotate the wheels of vehicle. These are generally used in all automobile.
2. Rotary engine (Wankel engine)
In rotary engine there is a rotor which frees to rotate. The pressure force generate
by burning of fuel is exerted on this rotor so the rotor rotate and starts to rotate the
wheels of vehicle. This engine is developed by Wankel in 1957. This engine is not used
in automobile in present days.
According to fuel used:
1. Diesel engine
These engines use diesel as the fuel. These are used in trucks, buses, cars etc.
2. Petrol engine
These engines use petrol as the fuel. These are used in bikes, sport cars, luxury cars
etc.
3. Gas engine
These engines use CNG and LPG as the fuel. These are used in some light motor
vehicles.
4. Electric engine
It is eco-friendly engine. It doesn?t use any fuel to burn. It uses electric energy to
rotate wheel.
According to method of ignition:
1. Compression ignition engine
In these types of engines, there is no extra equipment to burn the fuel. In these
engines burning of fuel starts due to temperature rise during compression of air. So it
is known as compression ignition engine.
2. Spark ignition engine
In these types of engines, ignition of fuel start by the spark, generate inside the
cylinder by some extra equipment. So it is known as spark ignition engine.