The Various Parts Of a Car Engine and Diagram


An automobile engine is a positive displacement internal combustion engine with an intake, compression, combustion, and exhaust stroke. Its main job is to transform energy from fuel into working power.

In other words, it produces the power that makes the car move. The engine is the heart of your car. It is a complex machine built to convert heat from burning gas into the force that turns the road wheels.

The various parts of a car engine include the engine block, piston, valves, oil pan, combustion chamber, manifold, cylinder head, crankshaft, camshaft, timing belt, spark plugs, connecting rod, cylinder liner, piston ring, distributor, camshaft pulley, oil filter, flywheels, head gasket, crankcase, and water pump.

The internal combustion engine (ICE) combines fuel ignition and combustion to power vehicles. The engine transforms energy into heat and mechanical torque, serving as the heart of the car.

Now, let’s go deep to explain the various parts of a car engine, their functions, and diagram!


Parts of a Car Engine Diagram

Understanding The Basic Parts Of a Car Engine


Engine or Cylinder Block

The fundamental structure of the engine is the cylinder block or engine block, which is a significant component of engine parts. The three components that make up the engine’s cylinder block, cylinder head, and crankcase serve as its structure and major stationary body.


Pistons are the most important engine component compared to other parts. The piston is a cylindrical plug that rotates inside a cylinder. Engines with piston velocity of 1250 RPM will rise and fall 2500 times per minute. Learn about the various types of car engine here!

Different Types of Automobile Engine Explained!

Cylinder Head

Cast iron and an aluminum alloy are typically used to create the cylinder head. Gaskets are used to provide a tight, leak-proof connection between the cylinder head and block, which are connected by studs mounted to the block. Above each cylinder, the cylinder head contains a combustion chamber.


The part of the engine from which power is drawn is the crankshaft. All engine parts use it as one of their primary sources of power transmission.

The main component of the power transmission system where the piston’s reciprocating motion is turned into a rotational motion with the aid of a connecting rod is the crankshaft.


A shaft with cams installed on it is named a camshaft. A cam is a piece of equipment that converts the camshaft’s rotating motion into the follower’s linear motion.

The valves are opened by the action of a camshaft. There are several cams along the length of this part of the car’s engine, two for each cylinder, one for the inlet valve, and one for the exhaust valve.


The fuel/air mixture often passes through the crankcase before entering the cylinder in two-stroke engines, which typically employ a crankcase-compression arrangement (s).

There is no oil sump in the crankcase in this engine’s design. The majority of the oil in four-stroke engines is stored inside the crankcase, which normally has an oil sump at the bottom.

Timing belt

To synchronise the rotation of the crankshaft and camshaft in a piston engine, either a timing belt (also known as a cambelt), a timing chain, or a set of timing gears is employed.

In addition, the timing belt or chain in an interference engine is essential for avoiding piston-valve contact. Typically, a timing belt is a drive belt having teeth on the interior surface.

Engine Valves

Engine valves are necessary to regulate the timing of the entry of the air-fuel mixture into the cylinder and the exit of the combustion products from the cylinders.

These are situated at the engine cylinder’s inlet and outlet openings. When closed, the valves are snug against the valve seats.

Intake and Exhaust valves

Inlet and exhaust valves, respectively, control and regulate the charge (or air) entering the engine for burning and the exhaust gases exiting the cylinder.

The entrance valve is where the air and fuel combination enters petrol engines. Diesel engines’ intake valves, meanwhile, can only let air in. The exhaust valve’s goal in either scenario is to let exhaust gases out.

Oil Pan

The oil pan, or sump, is the term for the lower section of the crankcase. Set screws are used to secure it to the crankcase, and a gasket seals the interface to prevent leaks. When changing the oil, a drain plug is placed at the bottom of the oil sump to allow the dirty oil to be drained away. The sump is often made of a cast aluminum alloy or pressed steel sheet.

Combustion chamber

The region of the cylinder where the fuel/air mixture ignites is known as a combustion chamber. The fuel/air combination is compressed by the piston and ignited when it comes into contact with the spark plug, pushing the mixture out of the combustion chamber as mechanical energy. The Injector Nozzle, Piston, Spark Plug, Combustion Chamber, and other significant internal combustion engine components are all housed in the Cylinder.

Understanding The Basic Parts Of a Car Engine


The air-fuel mixture and exhaust gases are carried by separate sets of pipes that are connected to the cylinder head and are known as manifolds. To be able to withstand the high temperature of exhaust gases, it is typically made of cast iron. It comprises the carburetor flange, intake manifold flange for the tailpipe, throttle body flange, and air intake flange.

Intake Manifold

The intake manifold in an automobile divides airflow between the cylinders and houses the throttle valve and other components. In some V6 and V8 engines, the intake manifold can have multiple sections.

The intake air passes through the air filter, intake boot, throttle body, intake manifold plenum, runners, and cylinders before entering the engine. The throttle valve regulates the engine’s rpm by controlling the airflow.

Exhaust Manifold

The exhaust manifold, which collects engine exhaust gas from several cylinders and sends it to the exhaust pipe, is often a straightforward cast iron or stainless-steel unit.

It’s linked to the exhaust valves. Its design is identical to that of the inlet manifold. The exhaust manifold serves the same purpose in diesel and gasoline engines, transporting exhaust gas in either case.

Spark Plugs

In internal combustion engines, a spark plug is an electrical component that uses an electric spark to ignite compressed aerosol fuel. The use of the electrical component in mechanical tasks is important. To ignite the compressed fuel/air combination by an electric spark and maintain engine combustion pressure, a spark plug is a component that transfers electric current from an ignition system to the combustion chamber of a spark-ignition engine.

Connecting Rod

The connecting rod’s primary job is to change the piston’s reciprocating motion into the crankshaft’s rotating motion. To endure pressure and twisting forces, it must be light and strong enough.

The connecting rod is typically manufactured of alloy steel or duralumin by drop forging and has an I-beam cross-section. These days, it is also cast from spheroidal or malleable graphite C.I.

Water Pump

The water pump in a car is a belt-driven device that receives power from the engine’s crankshaft. The water pump pulls the cooled fluid from the radiator through the pump’s centre inlet and is constructed as a centrifuge. The fluid is then returned to the cooling system of the car after being circulated outward into the engine.

Timing Belt Drive Pulley

An exclusive type of pulley system with teeth or pockets along the outside of the pulley body’s diameter is a timing belt pulley. Power is not transmitted through the pulley’s teeth or outside pockets. Instead, they activate the pulley belt to aid with timing and prevent misalignment.

Oil Pan Drain Bolt

The oil drain plug is usually found on the oil pan at the bottom of the engine. During an oil change, it is used to drain the oil from your pan. In some instances, replacing the gasket is all that is required to fix an oil plug leak.

A new oil drain stopper can be necessary if the bolt or oil pan has been cross-threaded. To assist you in avoiding replacing the entire oil pan, a large oil drain plug may occasionally cut fresh threads.

Piston Ring

Piston rings are inserted into the grooves of the piston to create a strong seal with the cylinder wall in steam or internal combustion engines. The piston’s outside diameter is connected to a metallic split ring called a piston ring. In older designs, there were 2-4 compression rings and 1-2 oil control rings per piston, while recent designs typically have 3-1 compression rings and 1 oil control ring per piston.

The piston ring seals high-pressure gases from the combustion chamber entering the crankcase and allows heat transfer from the piston crown to the cylinder walls. It also ensures sufficient lubrication fluid on the cylinder walls during the piston’s travel, reducing cylinder wear. In engines, piston rings provide the following primary purposes:

  • sealing the combustion chamber to reduce gas leakage into the crankcase.
  • improving the piston-to-cylinder wall heat transfer.
  • ensuring that there is the right amount of oil between the piston and the cylinder wall.
  • limiting the amount of engine oil used by returning scraped oil to the sump.


A mechanical device called a flywheel stores rotational energy, a type of kinetic energy proportional to the product of its moment of inertia and the square of its rotational speed, using the principle of conservation of angular momentum. The engine produces torque, but it is not constant and fluctuates.

Cylinder Liner

In order to prevent the issue of cylinder wear, these cylindrical shapes are used in the cylinders. It is one of the most crucial structural components that make up an engine’s interior. When they become worn out, these can be changed.

They are constructed from an iron alloy with silicon, manganese, nickel, and chromium. These are typically centrifugally cast. These liners are corrosion- and wear-resistant.


The distributor in internal combustion engines with spark ignition and mechanically timed ignition is an enclosed rotating shaft responsible for delivering high voltage current from the ignition coil to the spark plugs in the correct firing sequence and duration.

Camshaft Pulley

An engine’s timing system uses a cam pulley to regulate the camshaft’s rate of rotation, which in turn regulates the poppet valves that control air intake and exhaust in the cylinders. The timing chain and cam pulley work together to synchronise crankshaft and camshaft rotation.

Oil Filter

To keep the engine in your automobile operating smoothly, it filters the motor oil to remove dangerous dirt, metal shavings, and debris. Without an oil filter, dangerous contaminants could enter your motor oil and ruin the engine. Your engine oil will stay cleaner and last longer if you filter out the trash.

That is all for this article, where I explained the various parts of a car engine. I hope you learn a lot. If so, kindly share with others. Thanks for reading; see you around!