How Does a Diesel Engine Work Step-by-step?

In order to understand the step-by-step process, let’s take a look at the diesel engine components and functions.

●    Block - As the foundation of the modern diesel engine, the block is where all the parts for the basic internal combustion process are contained. The block has an open space for each cylinder, where the combustion happens.
●    Pistons - The pistons create the bottom of the combustion chamber, moving up and down in the cylinder while the engine is working. The movement of the pistons creates the compression of the air that leads to combustion.
●    Cylinder Head - The cylinder head closes the top of the open space in the block to reach the chamber where combustion happens. This head can be one unit to cover all the cylinders or multiple units that cover a section.
●    Valves - With the cylinder closed by the piston at the bottom and the cylinder head at the top, there needs to be a way to allow fresh air in and the leftover gasses out. This is where the valves come in. There are usually two valves for taking in air and two for the exhaust for each cylinder.
●    Fuel Injectors - Now, there needs to be a way to get fuel inside the cylinder, so there is something to combust. These components are a complex part of the process, spraying fuel in very precise patterns with highly controlled timing.
●    Camshaft - Rather than relying on an electrical system for opening valves and fuel injection, most engines use a mechanical process. The camshaft’s revolutions control the timing of these events by lobes on the shaft that set them into motion.
●    Connecting Rods - These pieces connect to a piston head at the bottom arm and carry the force of the combustion to the crankshaft.
●    Crankshaft - The crankshaft transfers the linear motion of combustion (the up-and-down part of the combustion process) into a rotational motion.

Each piston moves in sync with one other piston to create balance in the engine. With a 4-stroke diesel engine, these parts all come together to produce the combustion event in four stages. These stages are:

1.    Intake stroke
The piston moves down to the bottom of the cylinder, creating negative pressure that draws air from the open intake valve to fill the cylinder with air.
2.    Compression stroke
The intake and exhaust valves are closed, and the piston moves from the bottom to the top, compressing air to create heat. At the end of this stroke, fuel is injected into the chamber.
3.    Power stroke
Ignited by the heat of the compressed air, the fuel explodes, driving the piston down and creating the power stroke that transfers energy to other parts of the engine.
4.    Exhaust stroke
The exhaust valve is opened, and the piston moves from the bottom to the top, pushing out all of the exhaust from the combustion event.

Cummins: Diesel engines for today and tomorrow

At Cummins, you’ll find the most powerful and reliable engines on the market today, that continue to evolve through key innovations. With a wide range of sizes and specifications, you’ll find a diverse engine lineup that will fit your specific needs, whatever they are. Find your perfect Cummins engine today. Cummins’ commitment to creating dependable engines with peak performance shows in their dedication to tomorrow’s engines. Cummins is always innovating and testing new ideas to bring you the best in diesel engine technology, following in the footsteps of Clessie Cummins and Rudolf Diesel.