Watch the video then read the following:
Definition: The spark-ignition or petrol engine is a form of internal combustion engine, which burns a mixture of air and fuel internally in an enclosed cylinder. The heat derived from the burning of the mixture is converted to mechanical energy, which is used in hauling the vehicle along the road.
Function: The function of the engine is to convert heat energy of combustion into mechanical (kinetic) energy, needed to pull the vehicle along the road.
Characteristics of Petrol Engine
The following are the major characteristics of the petrol engine
- It uses petrol as fuel
- Air and fuel are premixed before being forced into the cylinder for combustion process
- Carburetor is used to convert fuel stream into vapour before proper mixture of air and fuel is attained in the engine.
- Some modern petrol engine cars now dispensed with the use of carburetor and favour the use of electronic injection for greater efficiency.
- Spark – ignition is used to ignite the compressed air and fuel mixture in the combustion chamber.
- The compression ration is relatively very low as it ranges between 6:1 and 21:1
- It uses both air cooled and water cooled systems
- It is a reciprocating engine i.e. an engine that converts up and down movements of piston to rotary motion of the crankshaft
