2-stroke & 4-stroke Engine comparison

 

 2-Stroke Engine cycle in comparison to 4-stroke Engine:

 

2-Stroke Engine

4-Stroke Engine

2 strokes to complete 1 working cycle

4 strokes to complete 1 working cycle

Air intake through scavenge ports

Air intake through suction valves

Low Speed Engines

High Speed Engines

Higher power

Lesser power

Expensive parts

Cheaper parts

 

 

Advantages of 2-stroke Engines in comparison to 4-stroke engines:

 

Two-stroke engines do not have suction valves, hence simple construction.

Two-stroke engines have a high power-to-weight ratio (because the engine has twice as many combustions per second as a four stroke engine revolving at the same speed).

Two-stroke engines have the potential for about twice the power in the same size because there are twice as many power strokes per revolution.

Two-stroke engines are lighter, and cost less to manufacture.

 

 

 

Disadvantages of 2-Stroke Engines in comparison to 4-stroke engines:

 

Two-stroke engines don't live as long as four-stroke engines as its parts wears out faster due to the lack of a lubrication system.

Two-stroke engines require a mix of oil with the gas to lubricate the crankshaft, connecting rod and cylinder walls.

Two-stroke oil can be expensive.

Two-stroke engines do not use fuel efficiently.

Two-stroke engines produce more pollution.