What is An Engine And Different Types of Engine?

The engine is the heart of your vehicle. It’s a complex machine built to convert the heat from burning gas into the power that turns the road wheels. The chain of reactions that achieves this goal is set in motion by a spark that ignites a mixture of fuel and compressed air in a momentarily sealed cylinder and burns rapidly. When the mixture burns, it expands and provides energy to drive the vehicle. Let’s find out in detail What is An Engine And Different Types of Engine.

What is An Engine?

An engine is a machine that burns fuel and converts it into mechanical power. Most modern vehicles use internal combustion engines (ICE) that ignite fuel and use the reaction to move mechanical parts. Engines – such as those used to power vehicles – can run on a variety of different fuels, particularly gasoline and diesel in cars.

However, there are some alternative fuel types such as biofuels and natural gas. In thermodynamic terms, engines are commonly referred to as heat engines that produce macroscopic motion from heat. The heat in this case comes from the combustion of fuel in the engine, which moves pistons.

Mechanical heat engines convert heat into work via various thermodynamic processes. The internal combustion engine is perhaps the most common example of a mechanical heat engine, in which the heat from the combustion of a fuel causes rapid pressurization of the gaseous products of combustion in the combustion chamber, causing them to expand and drive a piston that rotates a crankshaft. Unlike internal combustion engines, a reaction engine generates thrust by expelling reaction mass according to Newton’s third law of motion.

Apart from heat engines, electric motors convert electrical energy into mechanical motion, pneumatic motors use compressed air, and clockwork motors in wind-up toys use elastic energy. In biological systems, molecular motors, like myosins in muscles, use chemical energy to generate forces and ultimately motion (a chemical engine, but not a heat motor).

Chemical heat engines that use air as part of the fuel reaction are considered air-breathing engine, e.g., Rocket, deep submerged submarines

Engineers measure engines by the number of cylinders and the volume of those cylinders. For example, a 350 V8 is an engine with eight cylinders arranged in a V formation and displacing 350 cubic inches.

In 2021, modern vehicle engines can be more easily understood once divided into their three primary categories, which include:

  • Internal combustion engines
  • Hybrid engine (Internal combustion engine + electric engine)
  • Electric engine

So, let’s discuss different types of engines one by one.

Types of engines

Basically, the engines are of two types, and these are external combustion engines and internal combustion engines.

1. External combustion engine

External combustion engines (EC engines) separate the fuel and exhaust products – they burn the fuel in a chamber and heat the working fluid inside the engine through a heat exchanger or the engine wall. The grandfather of the industrial revolution, the steam engine, falls into this category.

In some ways, EC engines work similarly to their IC counterparts – both require heat, which is obtained by burning matter. However, there are also some differences.

EC engines use fluids that undergo thermal dilation contraction or phase shifting, but whose chemical composition remains unchanged. The fluid used can be either gaseous (as in the Stirling engine), liquid (the organic Rankine cycle engine) or undergoing a phase change (as in the steam engine) – in internal combustion engines the fluid is almost always a liquid fuel and air mixture, which burns (changes its chemical composition).

Finally, the engines can either drain the fluid after use, as internal combustion engines do (open-cycle engines), or continuously use the same fluid (closed-cycle engines).

2. Internal Combustion Engine

The internal combustion engine is an engine in which the combustion of a fuel takes place in a confined space called the combustion chamber. This exothermic reaction of a fuel with an oxidizer produces high-temperature, high-pressure gases that can expand.

The defining characteristic of an internal combustion engine is that the expanding hot gases do useful work by acting directly to cause movement, such as by acting on pistons, rotors, or even pushing and moving the entire engine itself.

Two types of internal combustion engines are currently manufactured: the spark-ignition gasoline engine and the compression-ignition diesel engine. Most of these are four-stroke engines, meaning it takes four piston strokes to complete a cycle. The cycle includes four distinct processes: intake, compression, combustion and power stroke, and exhaust.

Spark-ignition gasoline and compression ignition diesel engines differ in how they deliver and ignite the fuel. In a gasoline engine, the fuel is mixed with air and then sucked into the cylinder during the intake process. After the piston compresses the fuel-air mixture, the spark ignites it, causing combustion.

The expansion of the combustion gases pushes the piston during the power stroke. In a diesel engine, only air is drawn into the engine and then compressed. Diesel engines then spray the fuel in a suitable, metered amount into the hot compressed air, causing it to ignite.

3. Hybrid engine

Quite simply, a hybrid combines at least one electric motor with a petrol engine to move the car, and its system recovers energy through regenerative braking. Sometimes the electric motor does all the work, sometimes it’s the gas engine, sometimes they work together. The result is reduced gas mileage and therefore reduced fuel consumption. Adding electrical power can even increase performance in certain cases.

All draw power from a high-voltage battery (separate from the car’s conventional 12-volt battery), which is replenished by capturing energy from deceleration that is normally lost to the heat generated by the brakes in conventional cars. (This is done by the regenerative braking system.)

Hybrids also use the gas engine to charge and maintain the battery. Automakers use different hybrid designs to accomplish different tasks ranging from maximizing fuel savings to keeping vehicle costs as low as possible.

4. Electric engine

Unlike a typical internal combustion engine (ICE) vehicle, which runs on gas, electric vehicles do not require explosive combustion from combusted fuel to generate the energy needed for locomotion. Instead, they use the electrical energy stored in their batteries to power the electric motor(s) connected to the wheels and propel the car forward. As a result, electric vehicles have fewer moving parts than a gasoline vehicle and generally require less maintenance, although they currently have a higher initial cost.

different Types of internal combustion engines

The classification of the engines depends on the types of fuel used, the work cycle, the number of strokes, the type of ignition, the number of cylinders, the arrangement of the cylinders, the arrangement of the valves, the types of cooling, etc. These engines are used in various areas such as the automotive industry, aircraft industry, shipping industry, etc. depending on their suitability in different areas. So let’s discuss the different engines types one by one.

Types of Engine

V Style Engines

This used to be the most common car engine on the market and is still heavily used by car manufacturers today.

V-engines, one of the most common engine types, have their cylinders arranged in a V-shape and always have an even number of cylinders – the same number on either side of the V. These engines are usually arranged at a 90-degree angle and are typically found in 6, 8, 10 or 12 cylinders.

V Engines Pros and Cons:

  • V type engines usually boast of high-quality engine displacement and a rigid design.
  • They are expensive to maintain and complex for people to understand.
  • Compact and allows for more cabin space.
  • Ideal for larger family vehicles, trucks, and other automobiles where greater power and towing capacity is required.

Examples of vehicles commonly found in our inventory section with V-style engines include:

  • Ford Expedition
  • Honda Ridgeline
  • Ford F-150
  • Honda Odyssey

Inline Engines

In-line (or “straight”) engines have all the cylinders in a row, meaning they tend to be longer than the V configuration. For this reason, in-line engines are usually found in 3-, 4-, 5- and 6-cylinder variants, as 8 cylinders in a row would be too long to fit in most engine compartments. BMW is famous for its powerful “line sixes” (in-line 6-cylinder engines). In-line four-cylinder engines have been extremely popular in recent years due to their affordability, fuel economy and reduced emissions.

Some examples of great, quality used vehicles that have inline engines are:

  • Mitsubishi Mirage
  • Honda Accord
  • Buick Regal
  • Chevrolet Cruze

Pros and Cons of an Inline Engine

  • These engines are compact and lightweight.
  • They are easy to fix.
  • They are rather delicate engines.

When shopping for a used sedan, compact, or fuel-efficient vehicle, you should expect to find one with a 4-cylinder inline engine. Their compact size, lightweight materials, and good fuel efficiency make them ideal for powering smaller sized passenger vehicles.

Flat engines

Flat engines (also known as “boxer” engines) are arranged with the cylinders aligned horizontally so that when they fire, they face each other (as if boxing each other). A boxer engine is essentially a V-style engine where the V is opened to lie flat. Boxer engines are known to be used in Porsches and some Subaru models.

Motorcycles, such as ones made by BMW in 2021, largely rely on two-cylinder flat engines.

High-performance vehicles with flat engines have included the JaguarXK6,

Pros and Cons of Flat Engines

  • Vehicles with flat engines are well balanced and easy to handle.
  • They can be huge engines and rather complex to understand.

Rotary Engines

A rotary engine is an internal combustion engine, like the engine in your car, but it works very differently from the traditional piston engine.

In a piston engine, the same volume of space (the cylinder) alternately performs four different tasks – intake, compression, combustion and exhaust. A rotary motor does the same four jobs, but each happens in its own part of the case. It’s like having a separate cylinder for each of the four jobs, with the piston continuously moving from one to the next.

Pros and Cons of Rotary Engines

  • These engines are simple to understand.
  • They are durable engines.
  • Very hard to find skilled mechanics in case of failure.

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