Car Engine Parts – Pistons, Crankshafts and More

What are the Main Parts of a Car Engine?

There are different types of engines in automotive. Around these types, are two-stroke ones, and four-stroke ones. In general, internal combustion engines are the most common type in automotive. Here, we explain the general parts of an internal combustion engine. You will see that the general working principles of car engine parts are very simple. You can find detailed information about these engine components and parts;

  • Cylinder block
  • Cylinder head
  • Crankcase
  • Oil sump
  • Engine pistons
  • Piston rings
  • Gudgeon-pins
  • Connecting rods
  • Crankshaft
  • Crankshaft journals
  • Camshaft
  • Timing belts
  • Intake and exhaust manifolds
  • Intake and exhaust valves
  • Spark plugs,
  • Flywheel
  • Oil filter
  • Water pump

What are the Components of a Car Engine?

General parts of a car engine.
Image Source: Pinterest.

In our daily life, we use cars. Every car has a power production unit which we call engines. They are generally internal combustion type. It is very important to know how an internal combustion engine works. To understand how it works, you need to understand the general parts of an engine.

Firstly we need to state that, it is very important to know these parts. If you know the general parts of an engine, you can always have an idea about the general faults and breakdowns.

Also, if your profession is a engine, this article can be a very good summary for you.

Main Parts of Car Engine Structure

These are the main parts of anengine structure. These contain the other auxiliary parts of that constitute petrol motors.

Cylinder Block

Car engine cylinder block part.
Image Source: Wikimedia.

Cylinder blocks are the biggest part of engines. The general material of cylinder blocks is cast iron. Cylinder blocks are the structural part of a car engine where the piston holes exist. These holes contain the pistons where the combustion takes place. So, cylinder blocks are the very important structural part that holds the other parts of car engines.

Cylinder blocks must contain a feature of very good vibrational characteristics. Because a cylinder block needs to dampen the vibration of the rotary motion.

There are also head gaskets between the cylinder blocks and the cylinder head to prevent liquid leak.

The mechanical characteristics of cylinder blocks are also very important. A cylinder block must withstand the dynamic loads because of the movements of the cylinder inside it. Also, they should not lose their mechanical features at high temperatures. This is because there is a very big heat rise inside the cylinders.

Cylinder Head

Cylinder head.
Image Source:

This is another important structural element in a engine. Cylinder heads are the complementary structural elements that enclose the cylinder block and piston holes. There are sections on cylinder heads where manifolds and valves are attached to them.

The same important features for cylinder blocks are also valid for the cylinder heads. Because very high temperatures and dynamic effects of pistons and combustion will affect the cylinder heads.

The material of cylinder heads is also cast iron. So, metal casting methods are the general methods to produce cylinder heads and cylinder blocks. Additional machining techniques such as honing and surface finishing operations are applied to the holes and sections containing attachment points. Also you can find the head gaskets beneath this part.


The crankcase is one part with a cylinder block. But we can assume the crankcase is a separate section of an automotive motor. So, the crankcase is also a very important structural part of a engine. There are supports and holes for the crankshaft assembly and bearings of crankshaft assemblies.

Also, the same mechanical requirements for the cylinder block and cylinder head are valid for the crankcase. The same heat and dynamic loading effects are very important. Dynamic loading effects are important because of the crankshaft.

The material of the crankcase is cast iron again. Because crankcase is produced with the cylinder block.

Oil Sump

You can find the oil sump at the bottom of the general structure. At the bottom side of the crankcase, an oil sump is attached to contain the lubricant. There is a emboss geometry made from a material of aluminum alloys or magnesium alloys. It has a cup-like shape that oil stays here.

In general, we use different systems to provide the oil inside the oil sump. Around these systems, self-lubrication of the engine or the oil pumps.

Oil sumps must withstand the external damages coming from the bottom. So, we need to take care of the mechanical stability of the oil sump. For example, the vehicle moves on the road or at a grainy pace. There can be a stone that hits the oil sump. If the oil sump is pierced, all the oil will discharge and the engine will not work.

Head gaskets are also very important to prevent the oil infiltration.

Engine Pistons

Pistons, crankshaft, camshaft and timing belts.
Pistons, crankshaft, camshaft and timing belts(Image Source:

Maybe pistons are the most iconic parts of car engines. Because they are directly responsible to produce the power and mechanical energy.

Pistons are the elements inside the holes of engine blocks. With the effect of combustion inside the hole, the piston is thrust to the bottom side of the hole. So, pistons are the car parts that transmit the thrust force of the combustion through the connection rods.

Also, they are directly responsible of the general engine speed.

Small-end of the connecting rods is attached to the bottom sides of the pistons. Because of the rotary motion of the crankshaft, the piston comes to the top of the cylinder hole and goes to the bottom side with respective combustion.

This is the general cycle that pistons transfer the pressure and thrust to the bottom parts of the car engines.

According to the different types and structures of engines, there can be a different number of engine pistons. The most common number is 4 cylinders and 6 cylinders. So, pistons are a very important engine component that defines a feature of an engine.


This is the first car engine part that created the rotary motion. Because we need a rotary motion from motors. The engine produces reciprocating motion but parts of car engines convert it to rotary motion.

The crankshaft is the main part that rotates inside the crankcase. The crankshaft is assembled with connecting rods and flywheels. They take the reciprocating thrust from connecting rods and transmit this thrust to flywheels. Crankshafts define the engine speed directly.

The shape of the crankshaft is different from other general shafts. The connecting places of the crankshaft to connecting rods are eccentric and this structure provides rotary motion. Also, there are counterweights on the crankshaft that balances the dynamic effect of the up and down motion of the pistons.

The structure of the crankshaft must have very good dynamic stability. And also it must withstand very high dynamical loads. So, the design of crankshafts is somewhat different from the other types of shafts.


The flywheel is another important part of the car engine. The flywheel is a rotating disk that has a direct connection to the crankshaft. Thanks to the flywheel, the smooth working of the motor takes place. Because the power and rotational energy are very fluctuating in nature. So, the flywheel starts to rotary motion and stores angular momentum inside it. By measuring the rotational speed of flywheels, you can directly have an idea about the engine speed.

Once it starts rotating, stopping it is not easy because of the stored rotation energy. So, it provides much more smooth turning energy. This means increased comfort of the operation.

This decrement in the fluctuating rotary motion provides more life for engine parts and more smooth working for the passengers.

The flywheel collects this rotation energy by its moment of inertia and its rotational speed.

Smaller and Auxilary Part of Car Engines

These auxiliary parts are also very important. And they are assembled to the main engines.

Piston head and connecting rod.
Piston head and connecting rod.

Piston Rings

They are a very important part of a car engine. You can find the piston rings at the top of the pistons. There are circular rings on the top of the piston circumferences. They close the gap between the cylinder hole walls and pistons. Also, they provide controlled lubrication oil at the top of the piston heads.

Also, piston rings improve the heat transfer from the piston to cylinder walls. This is because the maximum heat should be dissipated from pistons to prevent damage from high temperatures.

The general materials of piston rings are high alloy steels and cast irons.

There are generally two piston rings respectively for each piston.


These are the mechanical pins that connect the cylinders and connecting rods. Gudgeon pins must withstand the forces and pressures that come from the cylinders. So, this is also a very important part of a car engine.

The mechanical strength of the gudgeon pins is very important. Because they will be exposed to cyclic loads because of the movement of the pistons. In the mechanical calculations, we need to consider the cyclic loads and fatigue of these pins. It is a small but important component.

Connecting Rods

Connecting rods are also very important components of engines. This is another component that transmits the thrust force from cylinder heads to the crankshaft. So, this is a very dynamic part of an engine.

Connecting rods are the mechanical elements between the piston head and crankshaft. It transforms the reciprocating motion of the head into the circular motion of the crankshaft. So, we need to consider the dynamical load effect for connecting rods also. There will be lots of effects of dynamical loads such as fatigue.

Very high engine speed can damage the connecting rods.

We call the top-end of connecting rods as small-end and the bottom-end of connecting rods as big-end. These are also very important terms about the components of engines.

Crankshaft Journals

Journals are the part of crankshafts where the connecting rods are mounted. The big end of the connecting roads is attached to the crankshaft journals. So, they are a very important component of engines to mention here.

The journals must have a very good surface finish. Because the friction between the journals and connecting rods must be minimum. Also, this section of crankshafts must withstand the dynamical loads.

Timing Parts of Car Engines

Motor timing is very important. Because the calibration of them is directly dependent on the timing parts. These timing parts are directly connected.


You can find the camshaft at the top of the motors. They are responsible for the timing of the motor. Timing is very important because we need to have a system where the opening and closing of valves must be perfect. Otherwise, they will not work as intended.

The crankshaft provides the rotary motion of the camshaft with timing belts. Also, the opening and closing force from the camshaft is provided by rockers and spring mechanisms. These are the very important parts of car engines. We need to calibrate the timing of the camshaft mechanism to obtain an optimum working cycle.

The egg-like shapes are rotating and rockers are touching these egg-like shapes. So, this dynamic relationship between the camshaft eggs and rockers provides the opening and closing action of the valves.

The mechanical strength of the dynamic loads on camshafts must be very good. Also, the wear characteristics of camshafts must be good to overcome the friction between the camshaft eggs and rocker’s arms. Also, there is required lubrication between the rocker arms and the camshaft to minimize friction.

Timing Belts

This is another important part of a car engine. As you understand from the name, the timing belts are very important for the calibration and timing of motors. You can see the timing belts beside the structure. Also, there are lots of pulleys that timing belts attached to them.

Once the motor starts working, the timing belt starts rotary motion with the inducing rotation of the crankshaft. The timing belt rotates around the pulleys of camshafts, ignition coils, and crankshaft. The diameters of pulleys are specially designed to obtain synchronous working of ignition coils, intake, and exhaust valves.

So, with the proper timing belt mechanism, we obtain a complete cycle of working. During the working, breakdown of timing belts is the most important damage. If these car engine parts are damaged, they simply will not work.

Also, very high engine speeds can cause damage to timing belts.

Also, there are other kinds of systems such as chain drives used in internal combustion systems. So, a more precise working and more rigid structure is provided with chain drive mechanisms other than belts.

The design and the adjustments of timing belts are not easy stuff. Special attention is required. The tightness and the working speed of belts are very important for an engine. So, it is a very important part of a car engine.

Ignition and Fuel Parts of Car Engines

Fuel supply and exhaust are also very important. Ignition of fuel creates the power.

Exhaust and intake parts of a car engine.
Manifolds(Image Source: bolatpartikü

Intake and Exhaust Manifolds

An intake manifold is a part of a car engine that distributes the airflow to cylinders. They obtain the required air and fuel mixture in desired ratios in the throttle valves. Air comes from outside with the vacuuming effect of the reciprocating motion of cylinders. The air come through the air filter and is mixed up with fuel. Then intake manifold distributes this air to cylinders.

Also, the exhaust manifold collects the exhaust gases from all the cylinders and sends these gases to the exhaust pipe and catalytic converter unit.

Head gaskets also prevent the leakage of the intake and exhaust liquids.

We need to design the intake and exhaust manifolds according to the fluid mechanics. We need to obtain the turbulent flow of air and fuel mixture. Because the burning of the air-fuel mixture is better for better-mixed air fuel. And also, we generally want the smooth flow of exhaust gases. Because, the more the smooth, the gases will be less harmful.

Intake and Exhaust Valves

Intake and exhaust valves are very important parts of the operation of a engine. As we stated above, timing belts are very important for the operation of these valves.

The intake valve is a mushroom-shaped element that opens while the cylinder moves downward. You can find these elements at the top of each cylinder. These parts are placed on the cylinder head. After the intake valve opens, the air-fuel mixture comes inside the cylinders. And it closes while the cylinder comes to the top side.

The intake valve is controlled by the camshaft mechanism. The eggs of the camshaft control the opening and closing of the intake and exhaust valves in synchronous motion.

Also, the exhaust valve opens after the burning of gases while the piston moves upward direction. So, gases are dashed from the piston. The exhaust valve closes and the intake valve opens.

These are the general working principles of the intake and exhaust valves.

Spark Plugs

Also, in the ignition engines, you can find the spark plugs between the intake and exhaust valves inside the cylinders. Spark plugs are the systems that give the electric spark for the ignition of the air-fuel mixture inside cylinders.

The working intervals of spark plugs depending on the engine speed.

They take the electrical energy from the ignition system which is also operated by the timing belt mechanism. The timing belt mechanism and the ignition system work together to obtain the synchronous working of the engine ignitions.

Oil Filter

There is a filter in most engines that filters the oil. In engine oil, there are lots of unwanted small particles that can harm the engine parts during the operation. So, the oil filter filters these particles inside the oil to obtain more clear oil for moving engine parts.

If the oil filter does not works well, unfiltered oil will harm your piston and cylinder liner systems.

Car Engine Parts for Cooling; Water Pump

Car engine cooling parts.
Engine cooling system(Image Source:

Cooling is very important stuff in cars. If there is no efficient cooling system in a engine, the will rise and eventual damage will cause the breakdown of the petrol motor. So, water pumps are very important parts of car engines.

Also with the increasing engine speed, the heat rises to higher temperatures.

Water pumps are circulating the water between the parts of the engine. It takes water from the cooling system, then pumps the cooled water to the engine. And water takes the excessive heat from the motor, and this heat is taken by the cooling system.

In a cooling system, there is a radiator that water passes in. This radiator has very thin channels. While water passes through these thin channels, it dissipates heat more efficiently. Also, there is a fan that directs air to the radiator which provides forced convection for the dissipation of this heat.

The water pump is operated by the timing belt also. After the crankshaft starts the rotary motion, the water pump starts working with the pulley and timing belt.

Also, the fan is worked by an electric battery.

Other Important Terms about Car Engine Parts

It will be very useful if you learn the additional information and terms about car engine parts below. They will complement your knowledge more. Check them below. You can find the definitions of these terms about the car engine parts;

  • Small-end of connecting rod
  • Big-end of connecting rod
  • Main-ends of crankshafts
  • Stroke-line of cylinders
  • Dead centers
  • Cylinder clearance volume
  • Crank-throw distance
  • Piston stroke
  • Cylinder bore

Small-End of Connecting Rod

This is the term that refers to the connection between the cylinder head and the connection rod. There is a gudgeon pin between the connecting rod and cylinder head. So, the connecting rod can rotate in one direction with this connection.

We call it a small end because the size of the connection is smaller than the size of the connection of the crankshaft.

Big-End of Connecting Rod

This refers to the connection between the crankshaft and the connecting rod. There is a journal connection that is bigger than the small end of the connecting rod.

So, there is an angular movement relationship between the crankshaft and connecting rod which provides the mechanism to convert the reciprocating motion to rotary motion.

Main-Ends of Crankshaft

Main-ends are the ends of crankshafts that connect the crankshaft with the crankcase. There are journals on the ends of crankshafts that are assembled into the crankcase. So, these main ends provide the rotation ability of the crankshaft.

An Important Term about Car Engine Parts; Stroke Line of Cylinders

Stroke lines are very important theoric lines for car engine parts. Cylinders follow these stroke lines go through their axes. The orientation of stroke lines defines the different constructions of engines such as boxer typesor V-types.

Also, we can state that the stroke lines are determined by the holes on the engine block.

Dead Centers

Dead centers are also very important terms for car engine parts. They define the positions of pistons inside the cylinders.

The top dead center(TDC) is the position of the piston which is the closest to the cylinder head. Pistons are generally at the top dead center right after dumping the burnt gases and right before the intake of the air-fuel mixture.

The bottom dead center(BDC) refers to the position of the piston which is furthest from the cylinder head. Pistons are generally at the bottom dead center at the end of the combustion and the intake of the air-fuel mixture.

Cylinder Clearance Volume

This is the volume of the cylinder. The volume consideration is made by the movement of the piston inside the cylinder. The height of this volume is the distance between the top dead center and bottom dead center.

The clearance volume is a very important term in lots of calculations related to internal combustion motors.

Crank-Throw Distance

In the structure of the crankshaft, this is the radial distance between the center of the main journal of the crankshaft and the big-end journals. This is a very important parameter in the intaking air-fuel mixture and exhausting the gases.

Piston Stroke

While talking about petrol engines, we generally use terms such as 4-stroke or 2-stroke. We need to know what a stroke means.

The stroke is the one movement of pistons between the top dead center and the bottom dead center of the cylinders. Also, this means that one stroke is the rotary motion of the crankshaft at 180 degrees.

For 4-stroke , 4-stroke movement creates one cycle; intake stroke, compression stroke, power stroke, and exhaust strokes.

There is no relation between the strokes and the engine speed.

Also for the 2-stroke, 2-stroke movements create one cycle. Intake and exhaust stroke and compression and power stroke.

Furthermore, the piston stroke is equal to twofold of the crank throw.

Cylinder Bore

We produce the engine blocks with sand casting applications. In the sand casting operation, we use the sand casting cores to obtain cylinder holes. But these holes have very rough surfaces. We need to apply additional boring applications to obtain optimum surface characteristics. 

So, because of this boring operation to obtain cylinder holes, we call them cylinder bores. Cylinder bores are a very important part of a car engine.

Why is this Information About the Car Engine Parts Important?

Cars are everywhere and each one has an engine. The most common type is the petrol engine. There can be different kinds of petrol engines but in general, their working principles are the same. So, you can be a driver of these cars.

It is very important to know the general technicals that you are using. Because you can be a more professional driver if you learn the general working principle of an engine. If you understand them, you will understand how a car works actually.

As you see above, there are lots of engine parts. Also, all of these parts are critical. Every part has a special duty inside an engine. So, if you learn the general working principles of these parts, it will be very easy to detect the problems of your car. There can be breakdowns. So, if you were able to know the general principles, you can make comments about the fault.

Maybe you can solve the problem on your own without calling the service. Also, repair expenses will be very low, because they can not make any change without your acceptance. After all, you know the problem.

So, you need to know what you are using.

For example, you can be a professional in car technicals. This can be a very important summary of the general parts of a car engine. This summary can remind you of all the working principles again.

Also, you need to know the general terminology about engines. Descriptions of different things about them are made by using these terms about engines. If you know the general terms above, you can explain the problems and other things about your engine to others.

Conclusion on Car Engine Parts

So above, we explained the general most important parts of a car engine to the audience. You can understand the general working principle of a petrol motor. You can also make different explanations about them.

Also, you can learn the general terms about petrol engines. You can use these terms while you are talking about engines. If you know these terms, they will think, you are a professional.

You can be a professional in these topics. This article can also be very useful for you. Because you have a very good summary about the car engine part and terms. You can remind yourself of the generals about them.

Finally, these are the general explanations of car engine parts and terms. We tried to give the information to all kinds of readers from beginners to professionals.

So, do not forget to leave your comments and questions below about the car engine parts and terms.

Your precious feedbacks are very important to us.

FAQs About Car Engine Parts

What are the all parts of a car engine? 

The general parts are; Cylinder block, cylinder head, crankcase, oil sump, pistons, piston rings, gudgeon-pins, connecting rods, crankshaft, crankshaft journals, camshaft, timing belts, intake and exhaust manifolds, intake and exhaust valves, spark plugs, flywheel, oil filter, and water pump. There are also other small parts which are the seals, head gaskets, and other sealing elements. Head gaskets are also very important.

Where is the engine on a car?

In general automobiles, the place of the it is on the front side of the car. If you open the bonnet of the car, the first thing you will notice is the engine. Maybe in some car models, they are placed at the rear side of the car such as the old models of Volkswagen Beetle. Also, the bonnet of these cars is on the rear side.

What parts does that engine block contain?

The general car engine parts that are assembled on the engine block are the cylinder heads, pistons inside the cylinder bore, and the crankcase below the engine block.

How many parts are in a car engine?

In an average internal combustion ones, there are around 200 parts. The main parts are listed above. Other parts are smaller parts and multiple parts that the engine contains. If you learn the general working principles of main car engine parts, it will be sufficient information for you. Other ones are generally related to the design.

Are engine parts affect the performance?

Yes. All the main parts are very important in the engine performance. For example, even the shape of the intake manifold affects the performance. So, during the design, the design of these parts has tremendous effects on the performance.

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