Advantages of two-stroke engine over four stroke engine

ADVANTAGES OF TWO - STROKE CYCLE ENGINE :

1. Cycle is completed in 2 - stroke or one revolution of the crankshaft.

2. It develops twice the number of power strokes than the four stroke engines.

3. For the same power developed , the two stroke engine is much lighter, less bulky and occupies less floor area.

4.Turning moment is more uniform and hence lighter flywheel is required.

5. It contains ports which are operated by the piston itself there fore no separate mechanisms are required.

6. Initial cost is low due to less complexity in mechanism

7. Mechanical efficiency is more.

8. Easy to start.

9. It can be done in either direction, which is useful in marine engines.

DISADVANTAGES OF FOUR - STROKE CYCLE ENGINE :

1. One cycle is completed in 4 stroke or two revolution of the crankshaft.

2. It develops half the number of power stroke than two stroke engine.

3. For the same power developed, the four stroke engine is bulky, heavier and occupies more floor area.

4. Turning moment is not uniform and hence heavier. Flywheel is required.

5. It contains the valves which are operated by separate mechanisms.

6. Mechanical efficiency is low.

7. It requires separate starting motor. '

8. It can be run in only one direction.

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