Internal Combustion Engine Parts And Metals From Which it is manufactured.

A metal decide the performance and limit of a machine. We are often interested in finding which metal is used in manufacturing of an IC engine and why. In manufacturing of an engine we have to use those metals which can handle the pressure and temperature of the engine and should be cheap in price. Today I am going to tell you about the metals which is used in IC engine and there method of manufacturing.

Cylinder block:

Cylinder is made by high grade cast iron because it is in direct contact of combustion gases. Cast iron has high compressive strength to handle the pressure and temperature. It is made by casting and usually cast in one piece.


Cylinder head:


The main function of cylinder head is to seal the cylinder and it should be light in weight. So cylinder head is usually made by cast iron or aluminum. It is made by casting or forging and usually in one piece.



Piston:

Piston is prime mover in engine so it should be light. It is in direct contact with combustion temperature and pressure so it should has high strength to handle this pressure. So generally piston is made by cast iron but sometime it is made by aluminum alloy. Usually it is made by casting.




 Piston ring:

Piston ring is usually made by fine grain of cast iron which has high elasticity and it is not affected by the working pressure. Sometime piston rings are made by alloy spring steel. It is made by forging.


Connecting rod:

Connecting rod transmits the power to crankshaft. It should have high strength. So it is made by alloy steel but in small engine it is made by aluminum to achieve lighter weight. It is made by forging.



Inlet valve and Exhaust valve:

Inlet valve admits the air and fuel into the cylinder. It is usually made by silicon chrome steel with about 3% carbon. It is made by forging.
Exhaust valve discharge the exhaust gases. It is made by austenitic steal. It is also made by forging.


Crankshaft:

Crankshaft converts the reciprocating motion of piston into rotary motion. It should have high tensile strength. So the crankshaft made by high tensile steel or sometime by cast iron. It is usually made by forging.

Piston Pin:

Piston pin is made by hardened steel so it can support and allow to connecting rod to swivel. It is usually made by forging.


Engine bearing:

Engine bearing should have lubricant property and strength to withstand in moving load. So its half is made of steel or bronze back to which a lining of relatively soft bearing material is applied.



Image source : http://dir.indiamart.com/indianexporters/au_engin.html



Difference Between Petrol and Diesel Engines.

According to the type of fuel used the I.C. engines are classified as petrol engine and diesel engine. And here I am going to tell you about the difference between the petrol and diesel engine.

Difference Between Petrol and Diesel Engine.



Petrol Engine

Diesel Engine
  •  

Works on otto cycle.
Works on diesel cycle.
  •  

Air-fuel mixture is sucked during suction stroke.

Air is sucked during the suction stroke.
  •  

Spark plug is used for ignition.

Spark plug is not used for ignition. compressed hot air is used for it.

  •  

Carburettor is used to inject air-fuel mixture within the engine during suction stroke.

Fuel injector is used to inject diesel after the completion of suction stroke.
  •  

Light in weight.
Heavy in weight.
  •  

Thermal efficiency is less (about 25%)

Thermal efficiency is more (about 40%).
  •  

Less space is required.
More space is required.
  •  

Problem of pre-ignition because of volatile nature of petrol.

There is no problem of pre-ignition due to less volatile nature of diesel.
  •  

Lower initial cost.
Higher initial cost.
  •  

Low compression ratio.
High compression ratio.
  •  

Fuel economy is high.
Fuel economy is low.
  •  

Lower maintenance cost.
Higher maintenance cost.


Types of Clutches

Types of Clutches

Before starting to study about different types of clutch, we must know about the meaning of clutch. Clutch is defined as the device which is used in automobiles to transmit power from one rotating shaft to another shaft. In cars it transmits power from the flywheel connected to the engine shaft to the clutch shaft, and from clutch shaft it is transmitted to the rear wheels through gear shaft, propeller shaft and differential.

Mainly clutches are divided into 2 parts:

  1. Friction clutches and
  2. Fluid flywheel

Friction clutches:

These clutches works on the principle of friction exist in between two rotating shaft when they come in contact with each other.

Fluid flywheel:

Fluid flywheel clutches works on transfer of energy from one rotor to the other by means of some fluid.

Types of friction clutches:

  1. Cone clutch
  2. Single plate clutch
  3. Multi-plate cutch
  4. Semi-centrifugal clutch
  5. Centrifugal clutch

Difference Between 2 Stroke and 4 Stroke Engines

In this post I am going to tell you about the difference between two stroke and four stroke engines.

Two Stroke Engine




Four Stroke Engine


S.No.

Four stroke engine

Two stroke engine

1. 
It has one power stroke for every two revolutions of the crankshaft.
It has one power stroke for each revolution of the crankshaft.
2.  
Heavy flywheel is required and engine runs unbalanced because turning moment on the crankshaft is not even due to one power stroke for every two revolutions of the crankshaft.
Lighter flywheel is required and engine runs balanced because turning moment is more even due to one power stroke for each revolution of the crankshaft.
3.  
Engine is heavy
Engine is light
4. 
Engine design is complicated due to valve mechanism.
Engine design is simple due to absence of valve mechanism.
5. 
More cost.
Less cost than 4 stroke.

6.  
Less mechanical efficiency due to more friction on many parts.
More mechanical efficiency due to less friction on a few parts.
7.  
More output due to full fresh charge intake and full burnt gases exhaust.
Less output due to mixing of fresh charge with the hot burnt gases.
8.  
Engine runs cooler.
Engine runs hotter.
9.  
Engine is water cooled.
Engine is air cooled.
10. 
Less fuel consumption and complete burning of fuel.
More fuel consumption and fresh charge is mixed with exhaust gases.
11.  
Engine requires more space.
Engine requires less space.
12. 
Complicated lubricating system.
Simple lubricating system.
13. 
Less noise is created by engine.
More noise is created by engine.
14. 
Engine consists of inlet and exhaust valve.
Engine consists of inlet and exhaust ports.
15.  
More thermal efficiency.
Less thermal efficiency.
16.  
It consumes less lubricating oil.
It consumes more lubricating oil.
17.  
Less wear and tear of moving parts.
More wear and tear of moving parts.
18.  
Used in cars, buses, trucks etc.
Used in mopeds, scooters, motorcycles etc.



Image Source: https://imgur.com/gallery/eatFH

How does a Four Stroke Diesel Engine (Compression Ignition Engine) Work?


Diesel engine which is also known as compression ignition engine is widely used in automobile industries. Many big vehicles such as truck, bus, car etc. used diesel engine as the power unit because of its higher torque and greater mileage than petrol engine. Diesel engine is very popular in Indian market as well as in other countries because of lower price of diesel than petrol in many countries. So the requirement of diesel engine is much more than petrol engine.
The ignition temperature of diesel is lower than petrol so the working of diesel engine is slightly different than petrol engine.
The power generation process in four stroke diesel engine is also divided into four parts. Each part is known as piston stroke. In IC engine, stroke is referred to the maximum distance travel by the piston in a single direction. The piston is free to move only in upward and downward direction. In four stroke engine the piston move two time up and down and the crankshaft move two complete revolution to complete four piston cycle. These are suction stroke, compression stroke, expansion stroke and exhaust stroke.

Suction stroke:

In the suction stroke or intake stroke of diesel engine the piston start moves from top end of the cylinder to bottom end of the cylinder and simultaneously inlet valve opens. At this time air at atmospheric pressure drawn inside the cylinder through the inlet valve by a pump. The inlet valve remains open until the piston reaches the lower end of cylinder. After it inlet valve close and seal the upper end of the cylinder.
How does four stroke diesel engine (compression ignition engine) works?

Compression stroke:

After the piston passes bottom end of the cylinder, it starts moving up. Both valves are closed and the cylinder is sealed at that time. The piston moves upward. This movement of piston compresses the air into a small space between the top of the piston and cylinder head. The air is compressed into 1/22 or less of its original volume. Due to this compression a high pressure and temperature generate inside the cylinder. Both the inlet and exhaust valves do not open during any part of this stroke. At the end of compression stroke the piston is at top end of the cylinder.
How does four stroke diesel engine (compression ignition engine) works?

Power stroke:

At the end of the compression stroke when the piston is at top end of the cylinder a metered quantity of diesel is injected into the cylinder by the injector. The heat of compressed air ignites the diesel fuel and generates high pressure which pushes down the piston. The connection rod carries this force to the crankshaft which turns to move the vehicle. At the end of power stroke the piston reach the bottom end of cylinder.
How does four stroke diesel engine (compression ignition engine) works?

Exhaust stroke:

When the piston reaches the bottom end of cylinder after the power stroke, the exhaust valve opens. At this time the burn gases inside the cylinder so the cylinder pressure is slightly high from atmospheric pressure. This pressure difference allows burn gases to escape through the exhaust port and the piston move through the top end of the cylinder. At the end of exhaust all burn gases escape and exhaust valve closed. Now again intake valve open and this process running until your vehicle starts.

How does four stroke diesel engine (compression ignition engine) works?