For a majority of people, a car is much more than just a machine that takes them from point A to Point B. For them, it grows on to become a friend, they treat it like a family member and not just another ‘machine’. As any person who loves cars would certainly tell you they find their cars to have a ‘character’, a ‘personality’ that captivated them.
Thus, knowing about our cars just as much as we know about our loved ones becomes an imperative for us. How they function, how they perform, what makes them the desirable piece of engineering that they are, and much, much more. But then, the field of automobile, its design, and engineering is a vast sea of knowledge and science. Yet, there are very many things that one must know about their cars, such as the significant car engine parts that join together to make your car’s heartbeat that wonderful addictive rhythm and lets you experience the power surge as you press the accelerator pedal.
Get to Know Your Car Engine; How Car Engine Works:
The modern car engine design is a fascinating thing to understand, they are marvels of engineering that work on complex parameters. However, in simpler terms, an engine makes a vehicle move by burning fuel inside it which in turn moves the wheels. Even though, in essence, this is correct, there is more that goes on inside an engine.
The engines we use in our cars are called Internal Combustion Engines or ICE and almost tall of the car ICEs across the world use one of the following as fuel: Petrol, Diesel, or CNG. The basic idea remains the same for all these fuel types, however, the way in which the ‘combustion’ and ‘supply of the fuel’ is achieved defines the type of engine. Thus, there are two specific types of internal combustion engines -
- The Spark Ignition engine (SI Engine)
- The Compression Ignition Engine (CI Engine)
The SI engines use petrol or CNG as fuel, while the CI engines are essentially diesel-fuelled ones.
Another important thing to understand about the way an engine works is to know how many times ‘combustion’ occurs per ‘cycle’. Here a cycle is defined as one completion of all strokes - intake, compression, expansion/ power and exhaust. Almost all modern engines have a four-stroke cycle where the combustion of the fuel is only one of the strokes. The four strokes in an internal combustion engine are Intake, Compression, combustion and power stroke, and the exhaust stroke. Here, a stroke is defined as a movement of a piston inside the cylinder from its lowest position to its highest position or vice versa.
Thus, when you put fuel inside your fuel tank and turn the ignition on, the following things occur:
- Intake Stroke - the fuel is supplied to the ignition chamber or inside the cylinder through a process that depends on your fuel and engine type. This fuel ‘sucked’ inside is actually a mixture of fuel and air. This is the first stroke in a four-stroke cycle in a modern ICE. In this stroke, the piston goes from its top position to its lowest position creating a vacuum that sucks the fuel into the chamber.
- Compression Stroke - This fuel and air mixture is then compressed by the piston which is coming up from its lowest position to its highest position. This generates extraordinary pressures inside the cylinder, causing the fuel and air mixture inside it to heat up. There is a small gap between the highest point to which a piston can travel inside a cylinder and the roof of the cylinder. This is where the compressed fuel and air mixture gets primed for the next stroke.
- Combustion and Power Stroke - In this stroke, the compressed air-fuel mixture is ignited. In the case of a Spark-Ignition Engine, there is a spark plug mounted on top of the cylinder that initiates a spark that ignites the air-fuel mixture. In a Compression Ignition engine, there is no need for a spark plug as diesel has a lower ignition temperature than petrol and the heat generated through compression and a support glow plug is sufficient to cause ignition of the fuel and air mixture. This ignition causes an explosion inside the chamber that thrusts the piston downwards. This part of the stroke is called the Power stroke and this is where the main power that runs your vehicle comes from.
- Exhaust Stroke - Once the expansion of burned gases inside the cylinder has pushed the piston all the way down, the gases are then pushed outside the combustion chamber through the piston that starts to come up again due to the inertia caused by the expansion of the gases in the earlier stroke.
Now that the basics of the four-strokes in modern internal combustion engines are clear. How does the power get transmitted to the wheels? Here is an overview of how this happens:
- Power stroke pushes the piston downwards.
- A piston is connected to the crankshaft which converts the vertical motion of the piston into a circular motion.
- The crankshaft turns the flywheel, a component that uses the principles of inertia to convert the power coming from the cylinder/s in pulses into a uniform flow.
- The flywheel is connected to the transmission via the clutch.
- The transmission is connected to the drive shafts that turn the wheels through live axles.
Now that you basically understand how a modern car's internal combustion engine works, in principle, it is time to discuss the 30 most significant car engine parts that you must know in order to understand your vehicle and the discussions around it. It can be helpful for you in case you need to repair or replace any part. Knowing what it does not only makes you understand its importance but also lets you be in a position where it will be hard for someone to scam you on service-related issues.
Car Engine Parts you must know:
Starting with our overview on important car engine parts first up is the engine block. An engine block can be understood as the metal casing inside which cylinder(s) and piston chambers are contained. Generally, the engine blocks are made of cast iron, however, in modern times, in order to keep the weights as low as possible and yet have the best structural rigidity to deal with much higher pressures inside the combustion chambers, and also for better heat management, various aluminium alloys are being used for the purpose.
A piston is a car engine part that is designed to travel in a straight line (up and down) inside a cylinder in a typical reciprocating engine. The pistons are used to push/ compress a fluid or gas in order to increase the temperature and pressure of the said liquid or gas. As we discussed above, a piston moves inside a cylinder to form the different strokes consisting of a cycle of power generation in engines. It works best in an air-tight or vacuum environment and is facilitated by the presence of piston rings that serve as a sealing component between the minuscule tolerances of the piston and the cylinder.
Just as the name suggests, a cylinder head is a car engine part that is used to cover up the cylinder block, thereby closing the entire engine and effectively forming the air-tight combustion chamber where the power generation through the engine occurs. A cylinder head also consists of the pathways through which the air and fuel flow into the combustion chambers while also having space for different valves (intake and exhaust) that can be multiple in numbers and different in sizes depending on the purpose or performance parameters of the engine. The cylinder head also has space for the likes of fuel injectors, spark plugs (in case of SI engines), glow plugs (in case of CI engines), etc. Most modern cylinder heads are made from aluminium.
As discussed above, the main function of a crankshaft as a car engine part is to convert the reciprocating movement of the piston into a rotatory motion, thereby helping convert the power coming in the form of pulses into a linear surge. In fact, a crankshaft is in itself an assembly of various smaller parts called - crank, shaft, crankpins, etc. By definition, a crank is a component that is attached to a rotating shaft at a right angle in order to either generate or receive a rotational motion or a reciprocating motion (as per the requirement) at the other end. The crankpins are the points at which the pistons are connected to the crankshaft through connecting rods.
A camshaft is a car engine part that connects the crankshaft with the cams. The cams are used to operate the valves for intake and exhaust in a typical internal combustion engine. The basic function of a cam is to convert a rotational motion into a linear motion and as such, cams are utilized in the engines for optimal opening and closing of valves, translating into desired management of engine RPM. The most common material used for camshafts is either cast iron or steel.
Timing Belt/ Chain:
A timing belt or a timing chain is a car engine part that is utilized to perfectly synchronize the movement of the crankshaft and the camshafts to enable the cams' facilitation of precise valve operation at the exact time as required by the engine design to provide the most optimal performance. Depending on the engine design, performance parameters, and other variables, an internal combustion engine might have a timing belt, a timing chain, or even timing gears in some cases. These timing belts or chains are sometimes required to be reset or replaced owing to wear and tear (belt slippage) or expansion of linkages of the chain that may cause less than ideal vehicle performance.
The function of a valve is to control the rate of flow of a fluid (liquid or a gas) through a system. There are mainly three types of valves used in an ICE:
- Poppet Valve - the most common type of valves that are seen in an automobile engine are the poppet valves. In common language, they are also known as Mushroom Valves. They are characterized by a small disc at the end of what is called a valve stem (a shaft). This disc is of the shape and size of the hole that it needs to seal in order to control the flow of a fluid. In ICE the placement of the intake and exhaust valves are such that the disc end is inside the combustion chamber for the intake valve while for the exhaust valve it is on the outside. Thus a lower pressure during the intake stroke opens the valve inwards sucking in the air-fuel mixture. While the higher pressure during the exhaust stroke pushes the valve head outwards.
- Sleeve Valve - as the name suggests, a sleeve valve is a valve made out of a machined sleeve in between a piston and the cylinder inside the combustion chamber. Through the movement of the piston over this sleeve and its location, the piston acts as either a suction component or an exhaust component. These types of valves are seldom used in modern ICEs.
- Rotary Valve - Another type of valve seldom used as a modern car engine part is the rotary valve. This valve functions with an engine specifically designed to utilize this mechanism's positive attributes, i.e., a rotary engine. At present, there are no rotary engine cars on sale in the market.
An oil pan is a car engine part that acts as a small reservoir for oil below the engine when the engine is not in use. It is also known as an oil sump.
A combustion chamber in terms of a car engine part is the inside of the cylinder where the actual burning of the fuel-air mixtures occurs. It is the space in between the cylinder head, cylinder liner, and the top of the piston when it is in its lowest position.
An intake manifold or inlet manifold is a car engine part that functions as the passage for the air and fuel into the cylinders through the inlet or intake valve.
An exhaust manifold is a car engine part that is designed as a pathway for the exhaust gases to escape from the combustion chamber. An exhaust manifold generally gathers exhausts from the various cylinders, this is done with the help of separate exhaust pipes which then merge into a lesser number of pipes to effectively control emission and other performance parameters.
Intake and Exhaust Valves:
The valves that are used to control the supply of air-fuel mixture into the combustion chamber are called intake or inlet valves while the ones that are designed to help exhaust gases escape from the combustion chamber into the exhaust manifold are called exhaust valves.
A spark plug is a car engine part that is used specifically in a spark-ignition engine (petrol or CNG) to help induce a spark into the heated air-fuel mixture after the compression part of the stroke. This yields in the mixture catching fire that in turn further facilitates the expansion of residual gases after the explosion, thereby creating power. An interesting trivia, the temperatures at the tip of a spark plug during spark production can be higher than the temperature of the surface of the sun, though for a minuscule amount of time.
A connecting rod is a car engine part that is used to connect a piston with the crankshaft. It is connected to the piston and the crankshaft in a way that helps transfer the piston’s reciprocating motion into a rotational motion at the crank.
A piston ring is a sealing component that is used to seal the minuscule tolerances between the piston and the cylinder sleeve inside the cylinder to help maintain a vacuum. A piston can have multiple piston rings and of different materials as well.
A gudgeon pin is a car engine part whose function is to join the connecting rod with the piston on one end and the crankshaft on the other end. This pin provides the bearing on each end to the connecting rod on which it can pivot during function.
A cam is a car engine part that is required for the proper opening and closing of intake and exhaust valves. A cam by definition is a component that can convert a rotational motion of a system into a linear one, thus finding great use in operations where opening or closing, or shutting off valves is required. The cams can be of various shapes and sizes depending on the type of the engine or its performance considerations.
A flywheel is a car engine part that is located in between the crankshaft and the clutch. Its main function is to store the energy produced by the engine through inertia, thereby converting the pulsating power production into a much more linear, usable and manageable flow. A Flywheel is essentially a thick disc suspended at a right angle to the axis of the crankshaft, thus creating a rotational motion with the movement of the crankshaft.
A gasket is a sealant used to provide an air-tight and leak-proof seal to engine casings. This saves us from any fluid loss during operation. These are usual spreadable adhesives that have abilities to withstand extreme pressures and temperatures.
A cylinder liner is a car engine part that is placed inside the cylinder and in between the cylinder wall and the piston to provide a smooth abrasion-free surface for the best and most frictionless movement of the piston inside the cylinder.
The covering that is utilized to cover the lower part of the engine that consists of the crankshaft, flywheel, clutch and gearbox among others is called a crankcase and is an important car engine part is usually made of aluminium.
An engine distributor is a device that is essentially a rotating switch used in engines with mechanical timing set for ignition. In modern-day cars, such functions are controlled by the electronic systems controlled by an ECU or an Electronic Control Module.
Distributor O Ring:
A distributor O ring is a car engine part that essentially is a mechanical gasket that is used to keep the distributor switch safe from the external environment inside the engine.
Cylinder Head Cover:
A cylinder headcover is a component that is used to cover the cylinder head externally in order to keep it sealed from the external environment and also to help with better heat management as well as NVH.
A rubber grommet is a small car engine part that is used to keep dangling wires or other components stay fixed at a place. It is generally a tube or a ring made of rubber.
A camshaft pulley is a car engine part utilized to drive the camshaft via the crankshaft. This is basically a setup that consists of two pulleys, (one bigger and one smaller) which is used to synchronize the cam operation vis a vis the crankshaft movement.
As the name suggests, an Oil Filter is a car engine part that is used to filter the lubricating oil that circulates across the engine in order to keep the engine internals safe from any catastrophic failure due to clogging or chipping. It is generally located inaccessible areas of the engine for quick removal and cleaning/ replacing.
Timing Belt Drive Pulley:
Just like the camshaft pulley, the work of the timing belt drive pulley as a critical car engine part is to help transmit and synchronize the cam versus valve lift ratio. It is used when a timing belt is used. In case your car engine has a timing chain, then there would be a sprocket instead of a pulley in the same location.
The car engine part used to supply water around the engine to help cool it is called the water pump.
Oil Pan Drain Bolt:
It is a quick access car engine part used for the purpose of draining the engine oil from the engine for replacement with new oil.
Common Engine Problems:
Here is a list of common engine problems and possible causes for them:
- Engine Overheating - Lack of coolant or its supply around the engine.
- Engine Cut-off - Electric or fueling issue. The battery might need recharging or there might be some issue with the fuel supply.
- Black Smoke - Improper combustion inside the cylinder. Needs spark plug changes, or the valve settings need to be reset.
- White Smoke - Engine oil inside the combustion chamber, piston, or piston rings might need a check.
- Idling RPM change - The timing belt/ chain needs a reset or the air-fuel mixture needs to be checked.
- Loss of Power - Valve setting issue, fuel supply issue, or an electric issue such as low charge in the battery.
Car Engine FAQ:
- What type of engine is used in cars? - It can either be a spark-ignition internal combustion engine or a compression-ignition internal combustion engine.
- What is the function of a car engine? - To generate power that makes the vehicle move on its own.
- What are the parts of a car engine? - The major parts of an Engine are the Cylinder Block, Cylinder Head, Cylinder, Piston, Crankshaft, and Flywheel, among others.
- How does a car engine work, step by step? - The basic flowgraph of working of a car engine is based on a four-stroke internal combustion engine principle. The fuel-air mixture enters into the cylinder at the intake stroke, it then gets compressed by a piston in the compression stroke, this stroke is followed by the combustion and power stroke in which the compressed fuel-air mixture is burned to produce heat and energy-yielding expansion of gases, and the last step is the exhaust stroke which helps the gases produced after the ignition to escape from the combustion chamber.
- Why won't my engine start? - You may have low fuel or a fuel supply issue or your car battery does not have enough charge to power the ignition.