Farm Power & Machinery

Comparison between two stroke and four stroke engine

 

Four stroke engine	Two stroke engine
One power stroke for every two revolutions of the crankshaft.	One power stroke for each revolution of the crankshaft.
There are inlet and exhaust valves in the engine.	There are inlet and exhaust ports instead of valves.
Crankcase is not fully closed and air tight.	Crankcase is fully closed and air tight.
Top of the piston compresses the charge.	Both sides of the piston compress the charge.
Size of the flywheel is comparatively larger.	Size of the flywheel is comparatively smaller.
Fuel is fully burnt.	Fuel is partially burnt.
Weight of engine per hp is high.	Weight of engine per hp is comparatively low.
Thermal efficiency is high.	Thermal efficiency is comparatively low.
Removal of exhaust gases easy.	Removal of exhaust gases comparatively difficult.
Torque produced is even.	Torque produced is less even.
All types of speed are possible (high and low).	Mostly high speed engines are there.
It can be operated in one direction only.	It can be operated in both directions (clockwise and counter clockwise).