An Engine is a device which transforms one form of energy into another form of Energy. An internal combustion engine is a heat engine where it undergoes different cycles of operations in a sequent manner to convert the thermal energy into useful work. In the previous articles, we have discussed the 2 stroke engine and the 4 stroke engines working principles, in this article we are going to compare the 2 stroke vs 4 stroke engine.
Working Principle of Engines
IC engines work on either Spark ignition or the Compression Ignition working principle.
Spark Ignition: Usually a petrol engine, where the combustion process of the air-fuel mixture is ignited by a spark from a spark plug
compression ignition: Generally the Diesel Engines, where the combustion process is caused by the elevated temperature of the air in the cylinder due to the mechanical compression.
Comparison of 2 Stroke vs 4 Stroke Engine
The following are the major differences between the 2 stroke and the 4 stroke engines. one of the major difference between the 2 stroke engine and the 4 stroke engine is that the method of taking the charge(Air/fuel mixture) into the cylinder. And exhausting the combustion products from the cylinder.
|One power stroke for one revolution of the crankshaft.
|One power stroke for two revolutions of the crankshaft.
|For greater output compared to the four-stroke engine.
Theoretically twice the power output than the four-stroke. (But actual practice the power is increased by 30%)
|Less power output than the two-stroke engine due to one power stroke for every two revolutions of the cranks shaft.
|Two-stroke engines will have the ports.
(Port: Fluid can be operated inward and outward direction)
|Four stroke engines will have the Valves.
(Valve: The fluid can be operated in one direction only)
|More uniform torque can be generated than the four-stroke.
|Less uniform torque can be generated than the two-stroke.
|Less effective fuel usage in two-stroke petrol engines.
(During scavenging, The inlet port and the exhaust port are open at the same time so that there is a chance of escaping of the fresh charge from the cylinder)
|More effective fuel usage.
(Due to valve operation four stroke engine have the full advantage of using the fuel efficiently)
|Less thermal efficiency with high fuel consumption.
|High thermal efficiency with less fuel consumption.
|Consumption of the lubricating oil is high.
|Consumption of the lubricating oil is low compared to Two-stroke engines.
|Due to the compact design of two-stroke and the high power output, these are used in motorcycles, scooter, and outboard engines.
|Four stroke engines are used in all four wheelers, trucks, heavy vehicles.
|Two stroke engine Cannot be able to operate the same efficiency at all speeds.
|Can be able to operate the same efficiency at all speeds.
These are the major differences between the 2 stroke vs 4 stroke engines. the 2 stroke engine and the 4 stroke engines are explained in detail in these articles: 2 Stroke, 4 Stroke. Please leave your thoughts in the comment section below.