DIFFERENCE between four stroke engine and two stroke engine

The basic differences are as follows;

• In 4 stroke one cycle is completed in 2 revolution of crankshaft where as in 2 stroke it completes in 1 revolution.

1. In 4 stroke one power stroke is obtained in every 2 revolution of crankshaft in four stroke one power stroke is obtained in everyone revolution of crankshaft.
2. 4 stroke the crown of piston is convex type whereas in 2 stroke the crown is concave type for maintaining high peak pressure and more combustion space.
3. Generally speaking in four-stroke valve mechanism is inlet and exhaust valve whereas in 2 stroke thare is only exhaust valve.
4. In 4 stroke for the same power developed engine are more bulky whereas in 2 stroke-can load more cargo because of high power to weight ratio.
5. 4 stroke for the same dimension ,develops half the power developed by two stroke Vs 2 stroke develops more power.
6. In 4 stroke mechanical efficiency is less due to presence of valve ,camshaft, rocker arm etc.
7. 4 stroke fuel oil cost is high
8. In 4stroke lube oil consumption is less but total lube oil cost is high due to the contamination of the lube oil.
9. In 4 stroke heavier flywheel Vs 2 stroke lighter flywheel