How Do Diesel Engines Work? Your Energy Questions, Answered. : ThyBlackMan

Wednesday, October 23, 2019

How Do Diesel Engines Work? Your Energy Questions, Answered.

July 11, 2019 by  
Filed under Opinion, Weekly Columns

Like Love Haha Wow Sad Angry

( The origin of the diesel engine dates back to the year 1893, in the hands of Rudolf Diesel.

Since their creation, diesel engines are in use mainly in the industrial field and in heavy vehicles.

This is due to their outstanding characteristics, including hardness and low consumption.

Ever wonder, “Exactly how do diesel engines work?” What makes this fuel different from others? We answer your energy questions in this guide.

What Is the Difference Between Diesel and Gasoline?

One of the most recurring questions when buying a car is fuel. The type of fuel that the vehicle uses, and the expenses matters!

The performance of the car and also its cost, are things you should take into account.

As most people know, certain fuels are useful in some cars. It can even be risky to mix some different fuels. Gasoline and diesel are two of the best-known fuels.

Let’s look at their differences!

What Is Gasoline Fuel?

It’s a mixture of hydrocarbons obtained from petroleum. This happens through the fractional distillation process, which is the lightest liquid fraction that can be obtained.

Gasoline requires more fuel to achieve higher torque, and its compression is low. It gets used in internal combustion engines.

What Is Diesel Fuel?

It’s a hydrocarbon density composed of paraffin. Similarly, you can use it in engines and also use it as heating fuel.

Diesel engines are thermal machines that work by alternative internal combustion. The combustion is the product of the self-ignition of the fuel.

It varies with respect to a gasoline engine in the type of fuel it employs. It includes gas-oil, diesel, or heavy oil petroleum products.

You can also use natural acetates, such as sunflower. In fact, the fuel that was initially used to put the diesel engine to work was peanut oil.

This engine followed the same four- cycle as gasoline. The idea was to have a more efficient thermal performance, using volatile alternative fuel.

Although gasoline and diesel engines are for similar tasks, the latter is preferable when you need more engine power.

You can also use diesel for backup generators. Find diesel fuel generator for sale here.

Oil for Diesel Engines

Engine oil keeps all the moving parts involved in the combustion process and engine operation of a machine refrigerated. For a better performance in power and durability of the diesel engine, we recommend sustainable and clean products.

To evaluate the quality of these lubricating oils, you must consider the viscosity.

Parts of Diesel Engines

A diesel engine that operates in four stages has the same components as the gasoline engine.

Diesel engines don’t have spark plugs. This is because the explosion gets achieved by compression and not by a spark. Diesel engines have more compression than gasoline engines. Their elements must be robust and resistant to withstand pressures.

The different parts of a diesel engine include:


These are pieces in the form of circular and self-tensioned that you place in the slots of the piston.

They serve as a hermetic mobile lock between the crankcase and the combustion chamber.

They prevent oil leaks when it passes into the combustion chamber while leaving a thin layer of lubricating oil on the walls of the jacket.

Engine Block

It’s a structure where you place the rest of the pieces. It includes crankshaft, camshaft, among others.

It has an opening where you place the cylinders, valve push rods, anti-freeze conduits, camshafts, and main bearings. It also has some holes in the top where you fasten the gaskets of the cylinder.

Cylinder Head

It is the part that closes each cylinder in the upper part. They support other components such as Rockers, valves, injectors, etc.


It’s a set of small cranks, one for each piston, located on the main bearings of the engine block. Its job is to convert the linear movement into a rotating motion.


These are structures that move from top to bottom. They are fundamental elements of the engine. They have 2 to 4 segments. The upper segment is for compression, and the lower segment is for greasing.


It is the rotating shaft that’s responsible for moving the cams. It also distributes the synchronized movement in the engine.


It is also known as a sump. It surrounds the crankshaft. It’s the component that closes the engine block and where most of the oil gets lodged.

Injection Pump

It‘s a device that raises the pressure of the fuel in the injection system to a higher level.

When injected, it enters the chamber sprayed to produce spontaneous inflammation.

It also distributes the fuel to the cylinders in the proper order of operation.

Transfer Pump

It’s responsible for continually feeding the injection pump, using a specific pressure.

They’re responsible for introducing the pulverized diesel fuel inside the combustion chamber.

They’re made up of a piston/cylinder assembly. Towards the end of the cylinder, it has a super-fine hole through which the fuel gets expelled at high pressure.

Spark Plugs

It’s an element that is used to help the diesel engine to start. Some of these engines, in cold conditions, have difficulties in starting.

The glow plugs direct heat to the block around the cylinders.

How Do Diesel Engines Work?

The operation of a diesel engine is the same as that of any thermal internal combustion engine.

It has auto-ignition due to the high temperatures offered by the compression of the air inside the cylinder.

They vary in relation to gasoline by not requiring a spark to ignite. The incandescent spark plugs raise the temperature of the chamber to improve the cold start.

It takes advantage of the heat when reaching the optimum temperature.

The Four-Cycle Cycle in Diesel Engines include:


Air filling occurs in the first operating time. The intake valve stays open as the piston goes down to its bottom dead center.

The total amount of air is always allowed to enter, regardless of the load condition. The colder it is, the lower the density and the more it’ll enter, increasing the combustion.


When the piston gets to the lower dead center, the intake valve gets closed. It then begins rising to the top, while contracting the air that is inside the cylinder.

The ratio is approximately 18: 1, and at this time, the temperature rises significantly.


Shortly before the piston reaches to the upper dead center, an injector atomizes the fuel into the chamber.

The fuel ignites immediately when it comes in contact with the air that is hot.

As you can see, you don’t need the spark that produces the spark plug, the heat it transmits is sufficient.


The high temperature generates pressure, driving the piston with force downwards. Some of the energy produced here is then used to return to the bottom dead center.

Burned gases are expelled, letting the cycle begin due to inertia.

Advantages of the Diesel Engine

Why is diesel cheaper? Diesel fuel is denser, so it evaporates more slowly. Little refining is needed to make diesel fuel. This makes it inexpensive.

However, from 2004, the demand for diesel increased due to various reasons. Besides, diesel has a higher energy density compared to gasoline.

If a diesel engine is this efficient, why is it not used more often? Diesel is ideal for large cargo transportation over long distances.

It is not always the best option for commuters. However, this rule keeps changing, as diesel engines get improved to make it less noisy and cleaner.

That’s why they have more output. Their sales have increased to the point of overcoming them.

When talking about prices, vehicles that use these engines are more expensive to purchase and maintain. It’s advisable to purchase a diesel automotive vehicle when you plan to travel for many kilometers. In this way, the difference in fuel consumption will compensate.

Durability and Long Life

As the combustion process is by air compression, they have less wear of the parts.

They also support more mileage, comparing to gasoline. They’re more durable and have less wear when they circulate at a few revolutions.


Since its inception in the late nineteenth century, the diesel engine got adopted by heavy and hard work machines.

It’s more preferred, especially for its simplicity. It doesn’t require spark plugs, cables, distributor, rotors, etc.

Its resistant pieces make it more reliable compared to those of a gasoline engine.


A diesel engine is capable of rolling more than twice as far as the gasoline engine, consuming the same amount of fuel. This happens because diesel is denser than gasoline and consequently saves up to 30% of the consumption.

Drag Capacity

The diesel engine generates less mechanical torque. It’s known as torque, because of the low speed it produces.

As a result, there’s increased effectiveness in the ability to load or drag.

Bottom Line

Have you been wondering whether you should use a gasoline or a diesel engine? We’ve highlighted most of the things you need to know about diesel engines.

Still want to know how do diesel engines work? Bookmark our blog for more information on diesel engines.

Staff Writer; Ricky Jackson

Speak Your Mind

Tell us what you're thinking...
and oh, if you want a pic to show with your comment, go get a gravatar!