Everything You Wanted To Know About Types Of Engines

The device which can convert heat energy of fuel into mechanical energy is known as engine or heat engine. Engine is widely used in automobile industries or we can say that engine is the heart of an automobile.Because this is the reason why your car is running.Car Engine-Secured under the hood of the car, it usually looks like a gigantic confusing jumble of wires, tubes, and metal. After all, this is what turns all the energy into the mechanical form, allowing your car to run.As the Generation Transforming evolution of car engines runs parallel with the development of car models and designs.

Car engines come in a variety, with different features, but with the same purpose, of course.The classification of the engines depends upon the types of fuel used, cycle of operation, number of stroke, type of ignition, number of cylinders, arrangement of cylinders, valve arrangement, types of cooling etc. these engines are used in different areas such as in automotive industries, aircraft industries, marine industries, etc. according to their suitability they are used in different areas. So let’s discuss about different engine types one by one.

According To Fuel Combustion Type :-

Combustion, also known as burning, is the basic chemical process of releasing energy from a fuel and air mixture. Basically these engine are classified into two types :-
1. External combustion (E.C.) Engine :-
An External Combustion Engine can also be distinguished as heat engine .Where the 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 :-
Internal-combustion engine, one in which combustion of the fuel takes place in a confined space, converts chemical energy into thermal energy, to produce useful mechanical work. The combustion of air and fuels take place inside the combustion chamber that is an integral part of the working fluid flow circuit. In an internal combustion engine the expansion of the high temperature and high pressure gases produced by combustion apply direct force to component of the engine which consists of a fixed cylinder and a moving piston. The expanding combustion gases push the piston, which in turn rotates the crankshaft. Ultimately, through a system of gears in the power-train, this motion drives the vehicle’s wheels.. The force is applied typically to pistons, turbine blades or a nozzle. 

Air-fuel mixture in the combustion chamber is ignited, either by a spark plug (in case of SI Engines) or by compression (in case of CI engines). This ignition produces tremendous amount of heat energy and pressure inside the cylinder. This induces reciprocating motion in the piston.Power of the piston is transmitted to a crankshaft which undergoes rotary motion. The rotary motion is ultimately transmitted to the wheels of the vehicle, via a transmission system, to produce propulsion in the vehicle.As the combustion takes place internally inside the cylinder (a part of working fluid circuit) the engine is called internal combustion engine.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.

According to Number of Stroke's :-

Two Stroke Engine's :-

A two-stroke engine is a sort of internal combustion engine which finishes a power cycle with two strokes of the cylinder amid just a single crankshaft transformation. One up and down inside the cylinder to complete one crankshaft revolution during a single time of fuel burn. In this type of engine, the end of the combustion stroke and the beginning of the compression stroke happen simultaneously, which means the intake and exhaust functions occur at the same time. Two stroke engine has high torque compare to four stroke engine.These are generally used in scooters, pumping sets etc.

Four Stroke Engine's :-

A four-stroke engine is an interior ignition engine that uses four distinct piston strokes (intake, compression, power, and exhaust) to finish one working cycle i.e.two strokes upward (form BDC to TDC) and two strokes downward (from TDC to BDC) movement in one cycle of power stroke is called four stroke engines.A working cycle requires two revolutions (720°) of the crankshaft.This type of engines has high average compare to two stroke engine. These are generally used in bikes, cars, truck etc.

Six Stroke Engine's :-The six stroke engine has decided advantages over the traditional motors and may result in increased fuel-efficiency, reduced mechanical complexity and reduced emissions.As you know about the working process of four stroke engine is the piston moves down to suck in air and fuel, then the fuel pushes up to compress, then the spark plug fires and the burning gas forces the piston down. Then the piston moves back up to push up the exhaust.
The six-stroke engine adds two more strokes after the exhaust stroke. Water is injected, and as it turns into steam, it pushes the piston down. Then the piston comes back up to force out the steam. It's really simple.A six-stroke engine combines an internal combustion engine with a steam engine to turn some of the waste heat into power. The only catch is that you have to add a water tank to your car that's about the same size as the gas tank. The good news is that you can probably eliminate the radiator.

According to the arrangement of cylinders :-

Inline Engine's :-
In this type of engines, cylinders are positioned in a straight line one behind the other along the length of the crankshaft. They will be facing in the upward direction which is usually perpendicular to the car. Among its three different variants, inline-four is the most popular in the industry as it is compact, fuel efficient and gives a higher power to weight ratio than flat 6 or 8 engines.This sort of configuration in the engines can be seen in the wide variety of small and hatchback cars. The arrangement of the cylinder is simply straight in these engines.
V-type Engine :-
An engine with two cylinder banks inclined at an angle to each other and with one crankshaft in a way that they appear to be in a “V” shape when viewed from the top. known as V-type engine.The unique shape of the V engine substantially reduces the overall engine weight and length compared to the inline engines.
W-type Engine :-
An engine same as V-type engine except with three banks of cylinders on the same crankshaft known as W-type engine these engines are developed by the Volkswagen group. W type engine is made when 12 cylinder and 16 cylinder engines are produced.Manufacturers rarely use this engine and configuration in any of the modern cars. Cars like Bentley Mulsanne use it though.

Radial Engines :-

The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is called a "star engine" (German Sternmotor, French moteur en étoile, Japanese hoshigata enjin, Italian Motore Stellare) in some languages. The radial configuration was commonly used for aircraft engines before gas turbine engines became predominant.
Opposed cylinder Engine:-

In opposed cylinder engine, the cylinders are place opposite to each other. The piston and the connecting rod show identical movement. It is runs smoothly and has more balancing. The size of the opposed cylinder engine increase because of its arrangement.

According to Ignition Process :-

Petrol Engines /Spark Ignition (S.I)Engines :-

In petrol engines, the air and fuel (petrol) mixture is drawn during the suction stroke.The mixture is compressed to approximately 20 to 30 bar(compression ratio, 6 to 10) in the compression stroke, thus raising the temperature in the range of 400 to 500°C. The temperature reached after compression is below the auto-ignition threshold of the air fuel mixture and thus it is ignited with the help of a spark plug before the piston reaches the top dead center.

The petrol engines works on Otto Cycle(also know ad constant volume cycle).In Otto cycle combustion takes place at constant volume, as whole of the fuel is burned instantaneously as an explosion.

Diesel Engines/Compression Ignition (C.I) Engine's :-

In diesel engines, the air is drawn during the suction stroke, which is compressed to approximately 30 to 45 bar(compression ratio, 14 to 25), thus raising the temperature in the range of 700 to 900°C.Into this glowing hot air, the fuel(diesel) is injected through a nozzle and finely dispersed.It evaporates, mixes with air and ignites spontaneously.During combustion the pressure increase in the range of 55 to 75 bar. The burned gases, under full load , are at a temperature of about 600°C but in case of petrol engine it is 900°C.Thus it may be noted that diesel engines utilizes the heat of the fuel to a better degree and for this reason its fuel consumption is lower .

The diesel engine works on diesel cycle(also know as constant pressure cycle).In diesel cycle, the combustion takes place at constant pressure because burning takes place gradually, without an explosion as the fuel enters.

Electric Engines :-

Even-though, electric cars became somewhat popular in the late 20th century, the first ever electric car was produced way before in 1880s. Since 2008, due to concerns about increasing greenhouse gas emissions and hike in fuel prices, the growth in electric vehicles has seen a positive trend.

Unlike traditional IC engine powered cars, electric cars get power from their pre-installed rechargeable batteries. These batteries not only power the engine, but other electrical equipment’s too. An electric motor simply converts electrical energy into mechanical energy, to generate force.
Electric motors are more effective than traditional IC engines in converting stored energy. They also have higher on-board efficiency than diesel engines. 

According To Valve Arrangement :-

According to the valve arrangement of the inlet and exhaust valve in various positions in the cylinder head or block, the automobile engines are classified into four categories. These arrangements are named as ‘L’, ‘I’, ‘F’ and ‘T’. It is easy to remember the word ‘LIFT’ to recall the four valve arrangement.
L-head Engine:- In these types of engine, the inlet and exhaust valves are arranged side by side and operated by a single camshaft. The cylinder and combustion chamber forms and inverted L.
I-head Engine:- In I-head engines, the inlet and exhaust valves are located in the cylinder head. A single valve actuates all the valves. These types of engine are mostly used in automobiles.
F-head Engine:- It is a combination of I-head and F-head engines. In this, one valve usually inlet valve is in the head and the exhaust valve lies in the cylinder block. Both the sets of valve are operated by the single camshaft.
T-head Engine:- In T-head engines, the inlet valve located at one side and the exhaust valve on other side of the cylinder. Here two camshafts are required to operate, one for the inlet valve and other one is for the exhaust valve.

According To Type of Design :-

Reciprocating Engine:-

In reciprocating engine, there is a piston and cylinder, the piston does reciprocating (to and Fro) motion within the cylinder. Due to the reciprocating motion of the piston, it is called reciprocating engine. 2 stroke and four stroke engines are the common examples of reciprocating engine.

Wankel Engine's/Rotary Engine :-
The first Wankel engine was first developed by a German engineer named Felix Wankel in 1929. Now the Modern Engine was addpoted designed by Hanns Dieter Paschke.
Wankel engine is an Internal combustion e
ngine which is different from the piston cylinder arrangement .The Wankel engine is a type of internal combustion engine using an eccentric rotary design to convert pressure into a rotating motion instead of using reciprocating pistons .In a piston engine,four-stroke cycle intake, compression, combustion and exhaust takes place in the same volume of space (the cylinder) .Where as in case of Wankel Engine it was a completely different way than the conventional piston engine.In Wankel Engine four-stroke cycle takes place in a space between the inside of an oval- like epitrochoid shaped housing and a rotor that is similar in shape to Reuleaux triangle but with sides that are somewhat flatter. The very compact Wankel engine delivers smooth high- rpm power. It is commonly called a rotary engine , though this name applies also to other completely different designs.

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 types of Cooling System :-

On the basis of types of cooling, the engines are classified as:
Air cooled Engines:- 

In these engines, the air is used to cool the engines. In air cooled engines the cylinder barrels are separated and metal fins are used which provides radiating surface area that increase cooling. The air cooled engines are generally used in motorcycles and scooters.
Water cooled Engines:-

In water cooled engines, the water is used for the cooling of engine. Water cooled engines are used in cars, buses, trucks and other four wheeled vehicles, heavy duty motor vehicles. An anti-freezing agent is added in the water to prevent it from freezing during cold weather. Every water cooled engines has radiator for the cooling of hot water from the engine.

According to Application :-

Stationary Engine:-

Stationary engine is an engine in which its framework does not move. It is used to drive immobile equipment like pump, generator, mill or factory machinery etc.
Automotive Engine:-

These are the types of engines which are used in automobile industries. For example: petrol engine, diesel engine, gas engine are internal combustion engines falls in the category of automotive engine.
Locomotive Engine:-

The engines which are used in trains are called locomotive engines.
Marine Engine:-

The engines which are used in marines for boat or ship propulsion is called marine engine.
Aircraft Engine:-

Types of engine which are used in aircraft is called aircraft engine. Radial and gas turbine engines are used in aircraft propulsion.