Two Stroke engine vs Four stroke engine working

What is your interpretation when you listen the word "two stroke" and "four stroke" engine.  Here you can understand wha...

What is your interpretation when you listen the word "two stroke" and "four stroke" engine. 

Here you can understand what is two stroke engine and four stroke engine.

Let's start with two stroke engine

1. Two stroke engine working principle

    In a two stroke engine, the working cycle is completed in two strokes of the piston or one revolution of the crankshaft. It means piston movement will be two time(one:- Upward stroke second:- downward stroke) , these up down movement of piston is considered as two stroke, and during that time crankshaft rotate one revolution, over which piston is mounted. 

Here below attached figure can clear your doubt. 

                Two stroke engine working

2. Four stroke engine

      In a four stroke engine, the working cycle is completed in four strokes of the piston or two revolutions of the crankshaft. It means piston movement will be four time(two:- upward stroke and two:-downward stroke) 

               Four stroke engine working 

  

Four stroke engine working principal

Major difference between two stroke and four stroke engine In the 2 stroke engine it consists of one cycle with one rotation

In the 4 stroke engine it consists of one cycle with two rotations.

The inlet and the exhaust valves of the 4 stroke engine are replaced by 3 ports in a 2 stroke engine.

In 2 stroke engine the lubrication oil must be mixed with the petrol

In case of 4 stroke engine the lubrication and the fueling must take place separately

In the 2 stroke engine due to the presence of the lubrication oil, some of the lubrication oil must be combusted during the time of heat addition. Hence there is more friction and loss of work in 2 Engine

The power available in the 2 stroke engine is only 70% of the calculated power

In 4 stroke engine the power available is 90% of the calculated power

In 2 stroke engine the transfer port and the exhaust port are opened at the same time. Hence some fresh air fuel mixture will be escaped out of the engine cylinder, due to which there is loss of fuel.

For single cylinder engine the size of the flywheel is bigger than the 4 stroke engine.

Due to the above reason the 2 stroke engine on the roads are replaced by the 4 stroke engine

The overall efficiency of a 4 stroke engine is much higher than that of a 2 stroke engine.