How a Car Engine Works: Engine Parts and Functions Explained in Detail

Engine Parts and functions: Working of the Car Engine Explained

engine parts and functions

Welcome to an exploration into the car engine — the beating heart of the automobile, where pistons dance, and valves sing in harmony. Just as a conductor holds the strings of an orchestra, the engine lays the foundation for creating the modern masterpiece — propelling your car down the open road!

In this blog, we will take a closer look at car engines, break down the intricacies of their parts, and understand their functions. Whether you’re a petrolhead or just curious about what makes your vehicle’s heartbeat, this blog is for you. So, fasten your seatbelts and let’s get moving on this delightful adventure!

What is a Car Engine?

Engine Parts and functions: Working of the Car Engine Explained

In 1886, Carl Benz submitted his patent application for a ‘vehicle powered by a gas engine.’ This event defined a pivotal moment in history and patent number 37435 laid the foundation stone for the inception of the modern automobile. 

Just months after, in July 1886, the world witnessed the first public appearance of the innovative three-wheeled wonder, the Benz Patent Motor Car, model no. 1. Fast forward to today, and the car engine has evolved into a sophisticated marvel of engineering.

The car engine, at its core, is a complex assembly of components like pistons, valves, fuel injectors, and spark plugs, that work together to convert fuel into power that makes your car move.

Also Read: 10 Engine Maintenance Tips

Different Types of Car Engines

Car Engine

When it comes to car engines, there are a range of options that cater to various driving needs, budgets, and preferences. From the tried-and-tested petrol and diesel engines to the innovative electric and hybrid options, each type brings its unique advantages to the table. 

Let’s explore the different types of car engines and what makes them special:

Engine TypeTechnologyDescription
Petrol EngineInternal combustion engineThe most common type of car engine, petrol engines burn gasoline to create power
They are relatively simple and inexpensive to produce
They can be less fuel-efficient than other types of engines
Diesel EngineInternal combustion engineDiesel engines are more fuel-efficient than petrol engines, but they produce more emissions
They are also more expensive to produce
Naturally Aspirated EngineInternal combustion engineThese engines rely on the natural suction of air to draw fuel into the cylinders
They are simple and reliable, but they can be less powerful than other types of engines
Turbocharged EngineInternal combustion engineTurbochargers use exhaust gases to spin a turbine, which forces more air into the cylinders
This increases the power and fuel efficiency of the engine
Electric MotorsElectricElectric motors use electricity to power the car
They are very efficient, but they have a limited range
Hybrid EngineHybridHybrid engines combine a petrol or diesel engine with an electric motor
This improves fuel efficiency and reduces emissions
Inline EnginesInternal combustion engineInline engines have all of their cylinders in a straight line
They are relatively simple and inexpensive to produce, but they can be less balanced than other types of engines
V-Shaped EnginesInternal combustion engineV-shaped engines have their cylinders arranged in two banks, forming a V-shape
They are more balanced than inline engines, but they can be more expensive to produce
Boxer EnginesInternal combustion engineBoxer engines have their cylinders arranged horizontally, opposite each other
They are very low to the ground, which improves handling
Rotary EnginesInternal combustion engineRotary engines have a triangular rotor that rotates inside a chamber
They are very compact and lightweight, but they can be less fuel-efficient than other types of engines
Hydrogen Fuel Cell EnginesFuel cellHydrogen fuel cell engines use hydrogen to generate electricity
They are very efficient and produce zero emissions, but they are still in the early stages of development
Turbocharged and Supercharged EnginesInternal combustion engineTurbocharged and supercharged engines use forced induction to increase the power output of the engine
Turbochargers use exhaust gases to spin a turbine, while superchargers are driven by the engine’s crankshaft
Atkinson Cycle EnginesInternal combustion engineAtkinson-cycle engines are a type of internal combustion engine that is more fuel-efficient than traditional Otto-cycle engines
They do this by delaying the closing of the intake valves, which allows for a longer expansion stroke
Two-Stroke EnginesInternal combustion engineTwo-stroke engines are a type of internal combustion engine that completes the intake, compression, power, and exhaust strokes in two revolutions of the crankshaft
They are simpler and lighter than four-stroke engines, but they can be less fuel-efficient and produce more emissions
Variable Compression Ratio EnginesInternal combustion engineVariable compression ratio engines can adjust their compression ratio depending on the load on the engine
This can improve fuel efficiency and performance
Opposed-Piston EnginesInternal combustion engineOpposed-piston engines have two pistons in each cylinder that move towards each other
This eliminates the need for a connecting rod and crankshaft, which makes the engine lighter and more compact
Free-Piston EnginesInternal combustion engineFree-piston engines do not have a crankshaft
Instead, the pistons move freely in the cylinders and generate electricity or power other components
Stirling EnginesExternal combustion engineStirling engines use an external heat source to power a piston
They are very efficient and can run on a variety of fuels, but they can be slow to start and have a low power output
Compressed Natural Gas (CNG) EnginesInternal combustion engineCNG engines burn compressed natural gas instead of gasoline
They are more fuel-efficient and produce fewer emissions than conventional fuel-powered engines
W EngineInternal combustion engineW engines have three banks of cylinders arranged in a W-shape
They are very powerful, but they are also very expensive and complex to produce

Also Read: How to Check Used Car Engine Condition

Car Engine Components and Their Functions

Now, let’s take a closer look at the various components of a car engine, their descriptions, and their functions. 

Cylinder BlockThis is the engine’s foundation that houses cylinders and crankshaft and provides stability and supportStructural integrity, supporting key engine components
CylindersThese are the cylindrical tubes where the air-fuel mixture undergoes combustion to generate power for the engineContainment and combustion chamber for fuel-air mixture
PistonsPistons are the moving components inside cylinders that translate the combustion force into crankshaft rotationConvert pressure from combustion into mechanical energy
CrankshaftThis is the core component of the engine that converts piston motion into rotational power for the wheelsTransforming linear motion into rotational motion
CamshaftThe camshaft manages the control of valve opening and closing, ensuring precise synchronisation with engine cyclesRegulating the timing of intake and exhaust valve operations
ValvesIntake and exhaust valves control the flow of air-fuel mixture and exhaust gasesAllowing fresh air intake and efficient exhaust of burnt gases
Spark PlugsThis is the ignition source in petrol engines that creates a spark to ignite the air-fuel mixture to start the combustion process Initiating the combustion process by igniting the air-fuel mixture
Fuel InjectorsThese inject the right amount of fuel into cylinders and help maintain the correct air-fuel ratioEnsuring the precise ratio of air and fuel for efficient combustion
GasketThese are the seals between engine components and help prevent leaks and ensure airtight connectionsCreating a barrier to prevent fluid or gas leakage between parts
Timing Belt/ChainThey lead to better coordination between camshaft and crankshaft timing and help ensure precise alignment of engine partsSynchronising the movements of critical engine components
Oil PumpThis is the circulatory system of the engine that supplies lubricating oil to prevent friction and wear among engine partsDistributing oil to engine components to reduce friction and wear
Cooling SystemThis helps regulate engine temperature and prevents overheating by circulating coolantMaintaining the engine’s operating temperature within safe limits
Air FilterThis helps clean the incoming air by removing dirt and debris and ensuring a clean combustion processFiltering air before it enters the engine to prevent contamination
Exhaust SystemThis helps guide and filter exhaust gases, which helps reduce the noise and controls the emissions produced during combustionSafely expelling exhaust gases and minimising noise levels

Also Read: Petrol vs Diesel Engine: The Differences Explained

How Does a Car Engine Work?

Car Engine Work

A car engine is an intricate machine that converts fuel into motion through a series of precisely timed actions, called strokes. Let’s explore the different strokes which would help us understand this process in detail.

Here’s a step-by-step breakdown of the four strokes of the engine and how they work together:

1. Intake Stroke

  • The engine begins by drawing in air, a vital component for the combustion process
  • An air filter ensures that the incoming air is clean and free from contaminants
  • The throttle regulates the amount of air entering the engine, adjusting it according to the driver’s acceleration demands

2. Compression Stroke

  • With the intake of air, the piston moves upwards, compressing the air within the cylinder
  • The compression ratio is defined by the space within the cylinder when the piston is at its lowest point compared to when it’s at its highest point
  • This ratio impacts engine efficiency and power

3. Combustion Process 

  • In petrol engines, the spark plug generates a spark to ignite the air-fuel mixture when compressed
  • Diesel engines rely on the heat generated during compression to ignite the diesel fuel

4. Power Stroke

  • As the ignited air-fuel mixture expands rapidly, it creates high-pressure gases
  • These gases exert force on the piston, pushing it down within the cylinder
  • This piston movement generates mechanical power which helps turn the engine’s crankshaft

5. Exhaust Stroke

  • After the power stroke, exhaust valves open to release the burnt gases from the cylinder
  • The expelled gases travel through the exhaust system, which includes a catalytic converter to reduce harmful emissions

6. Repeat

  • These four strokes – intake, compression, combustion, and exhaust – are repeated continuously in each cylinder
  • The synchronised actions of multiple cylinders create a constant and smooth power delivery that propels the vehicle

Also Read: 5 Warning Signs of Engine Failure You Should Not Ignore

Engines That Redefined Reliability and Durability

Every now and then we have the privilege to come across a car engine that leaves a mark on the automotive landscape. From meticulous engineering to robust materials, and the simplicity of refined design, these engines have all the right ingredients to make them a success story.

Here’s a closer look at some of the most reliable and durable engines ever made: 

1. Toyota 22R Engine

The Toyota 22R engine, produced from the early 1980s to the late ’90s, is celebrated for its tenacious strength. Toyota used this powerplant in several of its vehicles, including the Toyota Hilux and Toyota 4Runner. Designed for durability, it was commonly used in off-road vehicles, and its sturdy cast-iron block and simple design contributed to its reliability. Many 22R engines have covered hundreds of thousands of miles without major issues, making them legendary among truck enthusiasts.

2. Honda B-Series Engine

Honda’s B-Series engines, which debuted in the late ’80s and were used in models like the Honda Civic and Acura Integra, are renowned for their longevity and performance. These four-cylinder engines were part of Honda’s VTEC lineup, incorporating variable valve timing for better power and efficiency. Their lightweight, aluminium blocks contributed to their reliability, making them popular among tuners and racers who pushed them to their limits.

3. Mercedes-Benz OM617 Engine

The Mercedes-Benz OM617 diesel engine was in production for over a decade, from the late 1970s to the early ’90s. These engines powered various Mercedes-Benz models, including the 300D and 300SD. Known for their resilience, these engines are often referred to as “million-mile engines” due to their ability to reach extraordinary mileage. The OM617’s overbuilt design, cast-iron construction, and straightforward engineering are the keys to its reputation for lasting a lifetime.

4. Volkswagen EA111 Engine

Volkswagen’s EA111 engine series, used in many of their vehicles like the Golf and Passat, is admired for its reliability. These four-cylinder powerhouses, which began production in the early ’90s, feature a simple, efficient design. Their iron blocks and durability make them a favourite among VW enthusiasts and mechanics who appreciate their longevity, even with regular maintenance.

5. Volvo Redblock Engine

The Volvo Redblock engine series, originating in the late 1960s and used in various Volvo models like the 200 and 700 series, is lauded for its dependable performance. These engines were engineered to withstand harsh Scandinavian winters and provided exceptional longevity. Their iron blocks, strong internals, and a reputation for reliability have cemented the Redblock’s place in automotive history as one of the most durable engines ever made.

The Bottom Line 

A car engine is a melody of complex engineering and intricate mechanical components. From the fuel-hungry petrol engine to the eco-conscious electric motor, there are different types of engines, each suitable for a different vehicle and requirement.

In this blog, we have covered the components, types, functions, and workings of car engines. So, whether you’re a motorhead or a curious individual, understanding the inner workings of your car’s engine can deepen your appreciation for this technological wonder. With this newfound knowledge, the road ahead is yours to conquer. All you have to do is to get started!

Also Read: 3 Cylinder Engine vs 4 Cylinder Engine


Q. How does a car move from the engine?

A car moves by harnessing the power generated by its engine, which converts fuel, such as petrol, into motion through a controlled explosion in the cylinders.

Q. How does a petrol engine work in a car?

A petrol engine in a car operates by igniting a mixture of air and petrol in its cylinders, creating controlled explosions that drive the pistons and ultimately turn the wheels.

Q. How long does a petrol engine last?

The lifespan of a petrol engine depends on factors like maintenance, driving habits, and the quality of the engine. With proper care, it can last for several years.

Q. What are the parts and functions of the engine?

The engine in a car consists of several essential parts, including the cylinder block, cylinders, pistons, crankshaft, camshaft, valves, spark plugs, fuel injectors, gasket, timing belt/chain, oil pump, cooling system, air filter, and exhaust system, each serving a specific function in the engine’s operation.