Classification of IC Enignes

After understanding External Combustion Engine and Internal Combustion Engine in last post lets understand what are the parameters on which IC Engines could be classified.

1. Number of Strokes - On the basis of number of stroke, the types of engine are :

• Four Stroke Engine: It is an engine in which the piston moves four times i.e.2 upward (from BDC to TDC) and 2 downward (from TDC to BDC) movement in one cycle of power stroke is called four stroke engines. [ TDC - Top Dead Centre and BDC - Bottom Dead Centre]
  
  
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• Two Stroke Engine: The engine in which the piston does two times motion i.e. one from TDC to BDC and other from BDC to TDC to produce a power stroke is called two stroke engines. 

 

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     2. Types of Fuel Used - On the basis fuel used :  

• Gasoline engine: The engine which uses petrol for its working is called petrol engine.

• Diesel engine: The engine which uses diesel for its working is called diesel engine.

• Gas engine: An engine using gas fuel for the working is called gas engine. 

3. Type of Ignition - On the basis of ignition, the engines are classified as:

• Spark ignition engine (S.I. engine): In spark ignition engine there is a spark plug which is fitted at the engine head. The spark plug produces spark after the compression of the fuel and ignites the air fuel mixture for the combustion. The gasoline engines are spark ignition engine

• Compression ignition engine (C.I. engine): In Compression ignition engine there is no spark plug at the cylinder head. The fuel is ignited by the heat of the compressed air. The diesel engines are compression ignition engine.

The below diagram depicts the basic difference between SI Engine and CI Engine, left one being S.I Engine ( Which has Spark Plug at the engine head ) and right one being C.I Engine ( having Injector at the engine head)

Difference between S.I and C.I Engine

 

   4. Number of Cylinders - On the basis of number of cylinders present in the engine :

• Single cylinder engine: An engine which consists of single cylinder is called single cylinder engine. Generally the single cylinder engines are used in motorcycles, scooter, etc. 

• Double cylinder engine: The engine which consists of two cylinders is called double cylinder  engine.  

• Multi cylinder engine: An engine which consists of more than two cylinders is called multi cylinder engine. The multi cylinder engine may have three, four, six, eight, twelve and sixteen cylinder.

The below image shows the number of cylinders 6 and 4 :

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   5. Arrangement of Cylinders - On the basis of arrangement of cylinders the engine classification:

• Vertical engine: in vertical engines, the cylinders are arranged in vertical position as shown in the diagram

• Horizontal engine: In horizontal engines, the cylinders are placed horizontal position as shown in the diagram given below.

• Radial engine:  The radial engine is reciprocating type internal combustion engine configuration in which the cylinders radiate outward from a central crankcase like the spokes of a wheel. When it is viewed from the front, it resembles a stylized star and is called a ‘star’ engine. Before the gas turbine engine is not become predominant, it is commonly used for aircraft engines.

• V-engine: In v types of engine, the cylinders are placed in two banks having some angle between them. The angle between the two banks is keep as small as possible to prevent vibration and balancing problem.

• W type engine: In w type engines, the cylinders are arranged in three rows such that it forms W type arrangement. W type engine is made when 12 cylinder and 16 cylinder engines are produced.

• Opposed cylinder engine: In opposed cylinder engine, the cylinders are place opposite to each other. The piston and the connecting rod show identical movement. It is runs smoothly and has more balancing. The size of the opposed cylinder engine increase because of its arrangement. 

 The diagram below depicts arrangement of Cylinders :

Arrangement of Cylinders

    6.  Types of cooling

• Air cooled engines: In these engines, the air is used to cool the engines. In air cooled engines the cylinder barrels are separated and metal fins are used which provides radiating surface area that increase cooling. The air cooled engines are generally used in motorcycles and scooters.

• Water cooled engines: In water cooled engines, the water is used for the cooling of engine. Water cooled engines are used in cars, buses, trucks and other four wheeled vehicles, heavy duty motor vehicles. An anti-freezing agent is added in the water to prevent it from freezing during cold weather. Every water cooled engines has radiator for the cooling of hot water from the engine 

7. Types of Design

• Reciprocating engine: In reciprocating engine, there is a piston and cylinder, the piston does reciprocating (to and Fro) motion within the cylinder. Due to the reciprocating motion of the piston, it is called reciprocating engine. 2 stroke and four stroke engines are the common examples of reciprocating engine.

• Rotary engine: In rotary engine, the rotor does rotary motion to produce power. There is no reciprocating motion. A rotor is present in the chamber which does rotary motion inside a chamber. Wankel rotary engine , turbine engines are the rotary types of engine.

Rotatory Engine

Reciprocating Engine