Difference: Two Stroke & Four Stroke Engines | IC Engines | Thermodynamics

Learn about the comparison between two stroke and four stroke engines.

Comparison # Two Stroke Engines:

1. Cycle completed in 2 strokes and one revolution of the crank shaft.

2. No valves, it has inlet, exhaust and transfer ports instead.

3. It has special raised deflector on the piston head to prevent fresh charge going out with the exhaust gases.

4. Have higher fuel consumption i.e., give less mileage per litre compared to similar 4-stroke engine.

5. Are more pollutant as some un-burnt charge can go out along with the exhaust?

6. Mostly use mist lubrication. Simple construction and relatively cheaper.

7. Theoretically, produces double power for the same speed of the engine.

Comparison # Four Stroke Engines:

1. Cycle is completed in 4 strokes and two revolution of the crank shaft.

2. It has inlet and exhaust valves.

3. No special piston head required.

4. Have better mileage.

5. Cause less pollution as compared to the 2-stroke engines.

6. Costlier than 2-stroke engines

7. Theoretically produces half the power.