The modern combustion engine is a quintessence of contemporary technology. However, if something goes wrong, problems might baffle a driver, and related terms concerning the engine become obscure. So, every individual requires some basic knowledge to understand how it works before using the same.

In this regard, if you want to know what an internal combustion engine is, this might be the correct place for you. If you wish to learn more about the same, continue reading this piece!

An internal combustion engine is a type of engine where the reactants and products of combustion serve as a working fluid for combustion. An internal combustion engine gains its energy from the heat released during the combustion of non-reacted working fluids, and this whole process occurs within the engine. Also, this process is part of the thermodynamic cycle of the device.

The useful work generated by the IC engine comes from the hot gaseous products of combustion, which act on surfaces like a turbine blade, a face of a piston, or a nozzle. Moreover, it can use gasoline, hydrogen, diesel fuel, methane, and propane gas as a working fluid.

As mentioned earlier, this fuel ignition process and the combustion of an IC occur inside an engine. Combustion, also known as burning, is a basic process for releasing energy from an air-energy mixture. An engine then uses some of this combustion energy to produce work.

An internal combustion engine comprises a moving piston and fixed cylinder, and the expanding gases push the piston, which then rotates the crankshaft. The spark ignites a fuel-air combination after a piston compresses it, resulting in combustion. Also, during the power stroke, the piston is propelled by the expanding combustion gases. This motion ultimately propels the wheels of a car through the powertrain's gearing system.

Moreover, there are two types of functioning in internal combustion engines as per the following classification–

• Spark ignition gasoline engine
• Compression ignition diesel engine.

The only difference between these two is how they ignite and deliver fuel. In spark ignition gasoline engine, during the intake process, air and fuel are combined before being drawn into the cylinder. This spark ignites after the fuel-air mixture is compressed by a piston, and then it sources combustion. Furthermore, during a power stroke, the piston is pushed by the expansion of combustion gases.

On the other hand, the air is taken into an engine before being compressed in the case of a diesel engine. For ignition, fuel is then sprayed into the heated compressed air by diesel engines in a precise proportion.

Here are the different types of internal combustion engines – 

• Fuel Used

Diesel

Petrol

Gas Engine

• Working Cycle Employed 

2-stroke engine

4-stroke engine 

• Methods of Cooling 

Air cooling

Water cooling 

• Nature of Thermodynamic Cycle 

Diesel Cycle

Otto Cycle

Dual Cycle 

• Method of Ignition 

Compression-ignition engine

Spark-ignition engine 

• Field of Application 

Automobile engine

Stationary engine 

Aero engine

Portable engine

• Speed of Engine 

Low-speed engine

Medium-speed engine

High-speed engine 

• Arrangement of Engine Cylinders

Vertical Engine

Horizontal Engine 

Radial Engine

V type engine

It is challenging to provide a singular answer to this question as the use of an IC engine depends on a particular vehicle. For instance, a diesel-type IC engine is used in heavy-duty vehicles, whereas its petrol counterpart is used in low-duty vehicles. However, in terms of efficiency, diesel beats the petrol type as it provides about 40% efficiency compared with 26% in petrol IC engines. Hence, if efficiency is concerned, diesel-type IC engines are far more efficient than petrol-type IC.

The IC engines are widely used in automobiles and different types of machinery, and a few of those are –

• Aircrafts
• Road vehicles, including motorcycles, scooters, buses, etc.
• Small machines such as chainsaws, lawnmowers, and portable engine generators
• Motorboats

Hence, an internal combustion engine is one of the most popular engine types when it comes to vehicles in India. For example, the Mahindra XUV 300 diesel is one of the best vehicles in the Indian markets and is a great competitor of EV 4-wheelers. However, before committing to a vehicle, it is important to understand what an internal combustion engine is, and the above sections have described it laconically.