Inside Automotive Engines: How They Work

As an engineer, you know that every impressive technological feat is made possible by a complicated system of parts that work together perfectly.

The automotive engine, which uses fuel to move cars, planes, tractors, buses, and motorcycles, may be the best example of this.

Whether you are an engineering student or a seasoned professional, you will learn something new about this important technology and the brilliant minds that made it possible.

So buckle up and join us on this educational ride through the heart of the automotive engine!

Introduction to Automotive Engines

Formal definition:

The fuel-consuming machine that provides the motive power for automobiles, airplanes, tractors, buses, and motorcycles and is carried in the vehicle.

So, if you want to save money on gas, the best thing we can tell you is to just take out your car's engine. Just kidding!

An engine is a complicated machine that turns the wheels of a car by turning the heat from burning gasoline into force. Which gives speed to something.

A four-stroke combustion cycle is used to turn gasoline into motion in an internal combustion engine, which is the most common type of engine.

This cycle has four parts: intake, compression, burning, and exhaust.

Types of Engines

There are different types of engines, like in-line engines with four cylinders or V-engines with six or eight cylinders.

The layout of the engine determines how big it is, how well it works, and how much power it has.

In-line engines are smaller than V-engines, which are longer and more complicated.

Main Components

The cylinder block, cylinder head, and crankcase are the most important parts of an automobile engine.

The engine's heart is the cylinder block, which is usually made of iron or aluminum alloy. It has cylinders that hold the pistons, which move up and down to make energy.

The combustion chamber is also in the cylinder block. It is where fuel and air mix to make combustion.

The cylinder head sits on top of the cylinder block. It has a spark plug, camshafts, and valves.

The camshafts control how the valves open and close, which controls how much fuel, air, and exhaust gas goes into and out of the combustion chamber.

The spark plug lights the mixture of fuel and air so that combustion can happen.

The crankcase is usually made of cast iron and is at the bottom of the engine.

It holds parts like pistons, the crankshaft, the camshafts, the timing chain, the oil pan, the oil filter, and so on. Together, these parts turn fuel into movement.

When a car is turned off, the starter motor gives the piston the force it needs to move down.

Improvements in Combustion Engines

In the past few years, there have been improvements in engine technology, such as direct fuel injection, turbocharging, and variable valve timing.

Because of these changes, the car uses less gas, has more power, and puts out less pollution.

Video: How does it work?

Tip: Turn on the caption button if you need it. Choose “automatic translation” in the settings button, if you are not familiar with the English language. You may need to click on the language of the video first before your favorite language becomes available for translation.

Types of Automotive Engines

There are different kinds of engines used in cars, which can be grouped by two things: the fuel type and the way the engine is set up (the number of cylinders) (cylinder configuration).

Petrol and diesel engines are the most common kinds of car engines, but there are other things that set one engine apart from another.

  • Straight or Inline Engines.

All of the cylinders in a straight/inline engine are in a line, facing up and usually perpendicular to the car.

This is the most common layout for family hatchbacks and smaller cars.

  • Breakdowns.

Flat engines have two banks of cylinders on either side of a single crankshaft.

  • V-Engines.

The cylinders in a V-engine are set up in two separate banks that form a V around the crankshaft.

  • W-Engines.

W-engines have three rows of cylinders that form a W around the crankshaft.

The way the cylinders are set up can also be different.

Small cars have three-cylinder engines, but turbochargers have made it possible to put them in bigger family hatchbacks as well.

Six-cylinder engines are usually found in high-end sports cars and performance cars. They can be set up in a V or in a straight line.

Supercars and luxury saloons have engines with eight or more cylinders, like V8s, V10s, and V12s.

Some of the highest-end Volkswagen Group cars have W12 engines.

Gasoline and Diesel Engines

In automotive applications, the main differences between gasoline and diesel engines are how energy is made, the type of fuel used, thermal efficiency, life expectancy, revolutions per minute (RPM), and torque.

  • Gasoline Engines.

Spark-ignited combustion is used in gasoline engines to mix gas and air before compressing it and lighting it.

Most of the time, gasoline engines have higher RPMs than diesel engines, but they have less torque.

  • Diesel Engines.

Before injecting fuel into the air, diesel engines squeeze it down, which makes the engine more thermally efficient and likely to last longer.

Because diesel has a higher energy density than gasoline, diesel engines use less fuel than gasoline engines.

How these different engine types are used in cars has changed over time and depends on how the car is meant to be used, how well it needs to perform, and how much fuel it needs to use.

Expansion of the Automotive Industry

The Development of the Automotive Engine

During the Industrial Revolution, the growth of the auto industry and the need for engines with more power led to the creation of internal combustion engines (ICEs).

These engines were originally made to run on liquid fuels, but they were changed so that they could run on gasoline.

In the 1900s, two-cycle and four-cycle engines were made, and it became possible to make a lot of cars at once.

Improvements to Liquid Fuel Conversion and Emissions Reduction

Engineers came up with ways to turn liquid fuels into vapors so that they could be used. This improved fuel efficiency and engine output.

To solve the problem of pollution from cars, computerized engine management systems were also made.

ICE emissions of criteria pollutants like nitrogen oxides (NOx) and particulate matter (PM) have been cut by more than 99% thanks to research and development over the past 30 years.

Advanced Combustion Engine Research and Development

Today, people are trying to make internal combustion engines run better and be better for the environment.

Research and development on advanced combustion engines focuses on new technologies like homogeneous charge compression ignition (HCCI) and opposed piston engines (OPE), as well as making powertrains more electric and hybrid.

Even though the number of electric vehicles is growing, ICEs are still important to the transportation industry and will be used for a long time to come.

Automotive Engine Size and Airflow

Most car engines are measured in liters, which is the total volume of all their cylinders.

If you make the engine bigger, it can sometimes make more horsepower and torque, but this is not always the case.

Air Flow Sensing in Automotive Engines

The vane meter and the hot wire are the two most common ways for an engine to measure how much air is coming in.

A spring-loaded air vane connected to a variable resistor is used by the vane meter to measure the amount of air going into the engine.

The hot wire mass airflow sensor, on the other hand, uses a resistive wire that hangs down into the airflow and is heated to a certain temperature

The incoming air then cools the wire, which changes the electrical current in a way that is proportional to the amount of air passing through.

The Kármán vortex sensor, on the other hand, is not a way to measure incoming air flow in a car engine.

Instead, it is a way to measure air flow speed by causing vortices in the airflow and then measuring changes in pressure caused by the vortices.

Automotive Engine Maintenance

Engine Oil Filters

Engine oil filters are an important part of making sure that a car's engine runs well.

They work to get dirt, oil, and metal particles out of the oil. This lets the oil flow smoothly, cleans the oil, and protects the metal parts.

Price, design, construction, and attention to detail are all important things to think about when choosing an engine oil filter.

Automotive Engine Management Systems

There are many ways to tune and change an engine management system to improve its performance.

Some ways to change the systems are to re-calibrate the factory ECMs, tune with piggybacks, interceptors, and other extra parts, and design, modify, and build intake manifolds.

Separately programmable engine management systems can also be used to change how well an engine works.

To get the best performance, it is important to make changes in a safe and reliable way.

Before making changes to your engine management system, you should talk to an expert or read up on the subject.

Engine Hours

Engine hours are the number of hours that an engine has been running since it was first made, even when the vehicle is not moving.

This metric is helpful for measuring the wear and tear on commercial vehicles, especially for keeping track of idling time, since the odometer does not record mileage when a vehicle uses a PTO to sit still for hours every day.

Engine hours can also be used to plan preventive maintenance and figure out how much a vehicle has been used.

The relationship between engine hours and miles can be used to make a complete plan for replacing vehicles, improve maintenance schedules, and keep track of how well a fleet is doing.

Modern engines have a part called an engine control module (ECM) that counts the number of times the engine turns and how long each turn takes.

Automotive Engine Control Modules

Automotive engine control modules (ECMs) use a number of security measures to make sure they work right and keep people from messing with them.

For example, they embed verification hardware and safety mechanisms, use automotive security standards like SAE J3061 and ISO/SAE 21434, and go through verification processes.

ECMs can also be protected by using plausibility checks to find signals that have been spoofed or changed.

This is done by comparing sensor values with hard-wired values to make sure they are correct. This makes it harder for bad people to make changes to the ECM.

Lastly, modern ECMs are made with computer parts like microprocessors that can quickly receive, interpret, and act on sensor inputs. This helps make sure that the system works right.

The EPA has a policy in place to make sure that the Clean Air Act's bans on tampering and aftermarket defeat devices are followed.

These bans last for the entire life of a vehicle, make it illegal for dealers to sell tampered vehicles that are already on the road, and require regular inspections of vehicles to make sure that the emissions onboard diagnostic systems are working properly.

Tuners, which are products that change an ECU, may be illegal aftermarket defeat devices, and using them or putting them in may be illegal tampering.

Use cases

Cars and other vehiclesCars, trucks, and buses are the most common places where automotive engines are used. These engines give the vehicle the power it needs to move forward. They are an important part of modern transportation.
Propulsion of AircraftAnother important place where car engines are used is in airplanes, where they provide the thrust needed for takeoff and flight. Most airplane engines are more powerful and efficient than car engines because they need to be able to create more lift and overcome the resistance of the air.
Agricultural EquipmentEngines from cars are often used in tractors and other types of farm equipment. These engines have to be strong and long-lasting enough to handle the heavy loads and hard work that come with farming.
Power GenerationThere are times when car engines can also be used to make power. Most of the time, these engines are used in generator sets, which are used to power homes and businesses when the power goes out.
Marine PropulsionBoats and other types of watercraft can also be powered by car engines. Marine engines are usually made to last longer and resist corrosion better than car engines because they have to work in the harsh marine environment.
RacingAnother way that car engines are used is in racing, where they power high-performance cars that can go very fast. Most racing engines are tweaked to get the most out of them, and they can make a lot more power than a regular car engine.
Lawnmowers and other small toolsFinally, car engines can also be used to power lawnmowers, chainsaws, and other small tools. Most of the time, these engines are not as strong as their bigger counterparts, but they still need to be reliable and efficient enough to handle daily use.



In conclusion, the car engine is an amazing piece of technology that has changed the way we travel and live.

Engineers have been at the forefront of making these amazing machines, from the first internal combustion engines to the most advanced hybrid and electric powertrains of today.

But the car engine is also a symbol of something deeper: our natural desire to push the limits of what is possible, break through barriers, and dream of a better tomorrow.

As we look to the future, it is clear that the automotive engine will continue to be an important part of our lives

It is the engine that powers the cars that take us to work, school, and other places.

But it is also a reminder of how powerful human creativity is, how willing people are to try new things, and how much the human mind can do.

So the next time you start your car, take a moment to think about the amazing engineering that makes it all possible, and remember that the possibilities really are endless.

Share on…