System of car

There are various systems involved in a car such as

1. Intake and Exhaust system

2. Lubrication system

3. Cooling system 

4. Fuel system

5. Electrical system

1. Intake and Exhaust system

           Intake and exhaust are 2 important operations for engine performance. As we are aware for the operation of engine combustion of air and fuel is performed inside the engine cylinder to attain power stroke and keep the engine running. 

So, let's analyse the path of the intake side

Fresh Air- Intake duct - Air Filter- Turbocharger- Charge air cooler- Intake manifold- Into Engine cylinder

•  If you will analyse closely path followed by fresh air is a little longer if a turbocharger is added. 
• Designer of the engine has to look very closely about path and amount of air to be taken inside the engine cylinder. 
• Path of air travelling via turbocharger has to be as small as possible to avoid loss of power and quick initial throttle or accelerator response. 
• Charge air cooler helps in reducing the temperature of compressed air for increasing density. 
• Hot air has less density and cold air is having more density. 
• So, by reducing the temperature of air density is increased.
•  It results in more air to be admitted inside the engine cylinder.     

Intake and exhaust basic engine cycle

Now, let's understand the exhaust side

Out of engine cylinder- Exhaust Manifold- Turbo charger- Catalytic converter- Muffler- Into Atmosphere

•  After exhaust stroke, exhaust gases are pushed outside engine cylinder.
•  This exhaust gases are hot, full of pollutants and produce a loud noise while coming out of engine cylinder. 
• Every Engine is so designed that pollutants released into the atmosphere should be as less as possible. 
• You might have heard about Euro norms for pollution and Bharat stage pollution norms to reduce pollutants coming out of the engine. 
• After exhaust manifold, exhaust gases are accelerated towards turbocharger to utilise kinetic energy to turn turbine of turbo used to compress air. 
• After turbocharger, exhaust gases are transferred to catalytic converter to reduce pollutants such as Carbon monoxide (CO) and Hydrocarbons (HC). 
• These pollutants are converted to carbon dioxide and water. But the noise level is still present inside the exhaust tailpipe. 
• Noise levels are reduced with the help of muffler or silencer. 
• It is made up of different sections where exhaust gases are diverted in a zig-zag manner into a fixed chamber which reduces noise level. 
• This exhaust gases during this travelling from cylinder to exit of the muffler have been cooled to an extent. 
• The travel path of exhaust has an important role in engine overall performance.

2. Lubrication system

• Lubrication is reducing metal to metal contact between two surfaces. 
• Lubrication system takes care of reducing friction between engine moving parts with respect to each other. 
• Lubrication is performed by synthetic oils specified by SAE grades such as 0W-40, 5W-30 and many more. 
• These grades ensure the quality of the oil is not changed or deteriorated with weather conditions. 
• Let's understand, 0W or 5W Stands for Winter or cold weather condition that ability to flow is maintained. 
• As we know in extreme cold weather conditions, liquids tend to convert into solid resulting in loss of lubrication ability in cold conditions. 
• So, 0W or 5W ensures the stability of oil to be retained even in cold temperatures to some extent. 40 or 30 stands for summer or hot condition. 
• As we are aware, liquids tend to lose their state to vapour at high temperature. So, to retain its ability to lubricate even at high-temperature synthetic oils are used. 
• Combined grade oils are generally used in automobiles to ensure good lubrication properties over a wide range of atmospheric temperatures. 

Lubrication system overview (Older version cars)

• Every engine must have a good lubrication system. 
• This lubrication system can be guaranteed by proper design of engine block, crankshaft bearing, cylinders, camshafts and many more components. 
• This lubrication can either by splash lubrication in small engines and forced lubrication in larger engines.
• Splash lubrication is a type of lubrication which lubricated by balancing masses scoop attached to the piston and connecting rod assembly are splashing oil inside the engine thereby lubricating engine parts. 
• Forced lubrication uses an oil pump and oil nozzles to lubricate engine parts. The oil pump is driven by the crankshaft. 
• As the speed of crankshaft is increased oil demand for lubrication is increased. So the oil pump delivers the amount of oil as per the requirement of the crankshaft. 
• Oil is delivered through various nozzles to engine parts. Camshafts are lubricated by timing chain which is dipped into the oil sump.   

3. Cooling system

•  The cooling system is used to reduce the excess temperature of the complete engine. 
• The cooling system is often considered as important system as it prevents overheating of the engine. 
• There are various parts involved in the cooling systems such as coolant pump or water pump, thermostat, radiator and coolant. Coolant is a mixture of Anti-freeze and water. Popularly used Anti-freeze is ethylene glycol. 
• Anti-freeze is added to water to provide cooling at various temperature ranges. Generally, mixing concentration is in the range of 40-60 (Antifreeze to water) or 50-50. The coolant pump is used to supply coolant inside the engine. 

Cooling circuit and radiator design

• A thermostat is used to divert the flow of coolant towards the radiator from the engine. This helps to maintain the temperature of the coolant at an optimum level. 
• The radiator is placed in front side of the engine compartment with integrated fan unit.
•  You might observe in your instrument cluster, the temperature of coolant ranging from 80-100 degree Celsius. 
• Up to 90-100 degrees it is considered as optimum for various range of cars. 
• But, Coolant temperature above 100 degrees is considered as abnormal and need to take care of preventing overheating. 

4. Fuel system

•  The fuel system is also an important system for running an automobile.
•  The fuel tank is a storage space for fuel generally placed beneath 2nd row of passenger floor space. 
• Fuel tank size is directly dependent on a different model and as per specific manufacturer. 

Fuel re-fueling into the tank

• Fuel pump, fuel lines, fuel rail and injectors are important parts of the fuel system. The fuel pump is important of the fuel system, which helps in supplying fuel from fuel tank to engine.
• When we say fuel, we are talking about petrol as well as diesel. In both fuel system, some parts are always common such as fuel tank, fuel lines, fuel injectors.
• But, as injection pressure of both engines is different and operation too. So, it is important to understand the different pressure for petrol and diesel.
• For petrol engines, the injection pressure is in the range of 5-8 bar with only one fuel pump in most of the cases. 
• For diesel engines, the injection pressure is in the range of 1400-2000 bar with two fuel pump (low-pressure pump and high-pressure pump.  

5. Electrical system

• Whenever you see a car some basic electrical components are always present such as battery, alternator, headlamp, tail lamp, interior lights and many more.
• Every component in the car is powered by a Battery. The battery is a power source for every electrical component. 
• But, the battery has to be maintained at a certain level of potential. Otherwise, with the use of a battery, it can be a flat or dead battery.
• So, an alternator is used to charge the battery while the vehicle is running.
• Also, during starting large amount of current is drawn by the starter to crank the engine. So, the main battery has to be sufficiently rated and charged enough to meet the starting of the engine.

Fuse box

• There are various electrical components used which are wired via fuseboxes and control units.
• All electrical wiring harness is distributed via fuseboxes. 
• A red coloured circle shows a jump-starting point for positive point and ground is connected to the body for a negative point while jump-starting.