Engine Components and Functionality

Engine components may seem hard to understand. When you look into your engine bay, I am sure it looks so confusing, but it’s a lot simpler than it may seem. Let us remove the engine cover and break down these components together.

Engine components are pieces of an engine that all work together in unison to create mechanical power. Each piece plays a specific role in the engine operation. There are about 22 unique engine components that make up a fully functioning engine. It all varies however, 4-stroke, inline 4’s, Inline 6’s or V6’s and V8’s engines are the most common engine found today across many vehicle types. For this reason, we will focus on these combustion engines. 

You will of course find significant similarities with different and bigger engine types. This is why it’s good to have an understanding of combustion engine components as a basis.

What you will learn about :

• What are the 3 major parts of a car engine?
  • Engine components in Cylinder head/ Engine head
  • Engine components in Engine Block
  • Engine components in Oil Sump/ Oil Pan
• How many main components does an engine have?
  • Top section engine components:
  • Middle section engine components :
  • Bottom section engine components:
• What are the basic engine components?
• What are the most important engine components?
• Conclusion

What are the 3 major parts of a car engine?

To understand the engine components as a whole, let’s break it down into three major sections. Three major sections referring to its position are the Top, Middle, and Bottom:

Engine components in Cylinder head/ Engine head

This Top section houses the engine parts responsible for engine intake, combustion and exhaust. It also has engine oil pathways for proper lubrication of these engine components. Cylinder heads are usually made of iron alloy or aluminum which is lightweight and has good thermal conductivity properties.

Engine components in Engine Block

This middle section of the engine houses the pistons connecting rods and crankshaft. These are all parts responsible for the process of combustion in an engine. The engine block also has pathways for water cooling and oil lubrication of the engine components it houses. Engine blocks are usually made from cast iron or an aluminum alloy. Both materials have advantages for engine application. Aluminum alloy is lightweight and has great heat transfer properties. Whereas cast iron engine blocks have reduced thermal expansion and are great on the durability side of things.

Engine components in Oil Sump/ Oil Pan

This bottom section is where the engine oil and engine pump sit. The engine crankshaft and crank pins sit low enough in the engine to where, when it’s rotating, it sits within both regions of the mid and bottom sections of the engine.

How many main components does an engine have?

An engine has about 22 different main parts that we consider important pieces that are a crucial part of its operation. In other words “for it to work”. Let’s start by dissecting the three main sections I mentioned above, the top, middle, and bottom.

Top section engine components:

• Cylinder head

This is the part of the engine that houses the components that are responsible for the combustion process. A process such as intaking air and fuel, igniting the mixture, then exhausting the results of that combustion.

• Camshafts 

Camshafts are responsible for the movement (opening & closing) of the intake and exhaust valves ensuring proper synchronicity for the engine’s four-stroke cycle.

• Spark plugs

Spark plugs are responsible for igniting the fuel-air mixture to ensure combustion takes place on demand. 

• Fuel Injectors

Fuel injectors are responsible for injecting a specific amount of fuel into the air intake or the combustion chamber as an integral part of the combustion process.

• Intake manifold

An intake manifold is responsible for air distribution into all cylinders. An intake manifold has pathways for each cylinder, distributing air for each cylinder’s needs. The size of an intake manifold will depend on the number of cylinders an engine has. The more cylinders an engine has the bigger or more intake manifolds it needs—some intake manifolds also house fuel injectors for a fuel-air mixture.

• Intake valves

Intake valves are engine components that are responsible for the entrance of air into the cylinder combustion chamber. They open and close at the right time letting in a specific amount of air for the combustion process. The intake valves are directly influenced by the camshafts.  

• Exhaust manifold

The exhaust manifold is an exit distribution system where the exhaust gasses flow. This is where the exhaust gasses exit the engine after the combustion process.

• Exhaust valves 

Exhaust valves are engine components that are responsible for letting the exhaust gasses out of the combustion chamber into the exhaust manifold. They open and close the exit for the combustion process to take place then exit after the process is done.

• Valve stems 

Valve stems are the long skinny part of the intake and exhaust valves that ultimately connect to the camshafts. This is how the camshafts can ultimately influence the opening and closing of the intake and exhaust valves. 

• Valve springs 

Valve springs are responsible for reacting the opposite way when the valves are in the open position. The springs exert force onto the ends of the valve stems closing them shut when the camshafts force them open.

Middle section engine components :

• Engine block 

An engine block is the main supporting structure of an engine. This engine block houses the parts that process combustion and convert it into mechanical power.

• Piston head 

Often refers to the heart of the engine. This engine component is responsible for taking on the load of the combustion process from start to finish. This includes taking in air, compressing it, combustion, and the exhaust.

• Piston rings

Piston rings are located around the piston head within the piston groves. This part is responsible for sealing off the engine’s combustion. The piston ring ensures that any parts of combustion don’t leak anywhere else into the engine, keeping the process in one area which is the combustion chamber. 

• Wrist pin 

The Wrist pin connects the piston head to the connecting rod. The wrist pin ensures both parts work together in unison.

• Connecting rod

The connecting rod is connected to both the piston head and the crankshaft. The connection the connecting rod makes between the two ultimately transfers the forces applied to the piston head to the crankshaft, rotating it. This is where mechanical power is created. 

• Journal Bearings

Journal bearings are the connection between the connecting rod and the crankshaft. This ensures better rotational movement when the engine is in motion. This part is constantly lubricated to ensure smooth rotation. Otherwise, the engine would experience micro welding, or engine cease, which are not good things.

• Crankshaft

The crankshaft is one of the main engine components that converts the piston’s vertical force into rotational force. This rotational force is essentially the mechanical force that can be used to spin a multitude of things that inspire moments or energy in a vehicle.

Bottom section engine components:

• Oil sump

The oil sump is the area at the bottom of the engine. where the oil and oil pump sits as a unique storage space for the engine’s lubrication needs.

• Engine oil

Engine oil is a specific liquid an engine uses for its self-lubrication. This Liquid is crucial to an engine’s health and longevity. Engine oil has a periodic changing cycle to ensure the proper function and lubrication of engine components. 

• Oil pump 

An oil pump is the motor that pumps oil through the engine’s lubrication system. An oil pump keeps up a certain oil pressure which is necessary for certain engine components.

There are other parts that connect the engine as a whole and these parts are: 

• Timing Belt/chain 

The timing belt or chain can be a rubber belt or chain as the name suggests. This part connects to the camshaft and crankshaft through gears. When rotation happens the timing belt/chain ensures that the rotating of the crankshaft and camshaft turn at a specific time to ensure the combustion process is executed. 

• Gaskets 

Gaskets are engine components that create a perfect seal between certain engine components to ensure no leakage of any kind.

What are the basic engine components?

The basic parts of the car engine will follow the fundamentals of what it takes for that engine to operate. In a combustion engine, for instance, the basic parts would be the engine components that ensure the combustion process. From the list I stated above, the basic engine components would conclude everything from all three sections. These sections are:

•  The Top – Cylinder head/Engine head

•  The Middle – Engine Block

•  The Bottom – Oil Sump.

What are the most important engine components?

An engine has a lot of crucial components for operation to take place. Especially a combustion car engine. A lot of these parts have to be built with durable material for them to stand up against the combustion process over a long period. But the most important part of an engine that any manufacturer has to get right is the pistons. Often referred to as the heart of the engine, the pistons are the engine components that take on the load of the combustion process. The pistons pass the forces of combustion onto the crankshaft, essentially converting that energy into mechanical power.

Conclusion

Now that you’re all up to speed on engine components you can begin to see the basic operation of any combustion engine you may be interested in. Now engines don’t have to be complicated anymore. If you want to know more about the basic operation of an automotive engine, don’t worry I’ve got you covered.