Types of Engine

What is the Engine?

An engine is a power-producing machine, which can convert the potential energy of the fuel used in an engine into heat energy and then convert it into motion.

The engine power is generated bat burning the fuel in a self-regulated and controlled combustion process. 

Introduction of Engine :

Engines vary in design, but certain elements are common to all engines and are used for engine classification which is following below.  

• The number of cylinders 
• The geometry of the block
• Type of ignition system used

The two major engine types of engine are spark ignition (gasoline engine) and compression ignition (diesel engine) which use different types of fuel. 

Types of Engine :

The following are ways engines are classified :

Fuel Burned :

According to fuel burned mainly, two types of fuel are used such as gasoline and diesel. 

Gasoline car engines use spark ignition engine.

Diesel engines use compression ignition (no spark.) 

Alternate fuels such as liquefied petroleum gas (LPG), gasohol (90% gasoline, 10% alcohol), and pure alcohol are used in very limited situations.

Block Geometry :

There are four types of engine block geometry: 

• V-type Engine
• Inline Engine 
• Horizontally Engine
• Opposed and slant Engine

Number of Cylinders :

The number of cylinders is often used in combination with the engine block geometry which can be shown above.  

• Two Cylinder Engine
• Three-Cylinder Engine
• Four Cylinder Engine
• Five-Cylinder Engine
• Six Cylinder Engine
• Eight Cylinder Engine
• Twelve Cylinder Engine
• Sixteen Cylinder Engine

Camshaft Location :

There are two types of engine classified as possible locations for the camshaft: 

• In the cylinder head 
• In the engine block. 

Car engines with the camshaft in the cylinder head are labeled overhead cam (OHC) engines. 

A dual overhead cam (DOHC) engine uses two camshafts, one camshaft for the intake valves, the other for the exhaust valves. 

Single overhead cam (SOHC) engines use one cam for both sets of valves. Engines with the camshaft in the block, “cam-in-block”, use push rods to move the valves. 

Combustion Chamber :

There are three shapes in use: 

• Hemispherical
• Wedge
• Pancake. 

The hemispherical, also called “Hemi-head,” is designed with the intake and exhaust valves angled and opposing each other (as viewed looking at the engine from front to back). 

The pancake design has the valves nearly vertical. 

Ignition Type : 

There are two types of engines classified by ignition type :

• Spark Ignition 
• Compression-Ignition

Strokes per Cycle :

There are two types of engines classified by strokes per cycle :

• Two Strokes Engine
• Four Strokes Engine

The number of times the piston travels up and down during one cycle is called strokes per cycle. Four strokes such as intake, compression, power, and exhaust. 

Cooling System :

There are two types of engines classified by the cooling system :

• Air-cooled  
• Liquid-cooled