Two- Stroke Engine-
A two-stroke engine produces more power than a four-stroke engine. The main power stroke is produced by two revolutions of the crankshaft, that’s why it’s called a two-stroke engine. The strokes are- Upward stroke and the other is the Downward stroke. In this type of engine, the crankshaft revolves only 360 degrees to produce a single power stroke, That’s why it has more power efficiency than the four-stroke engine.
Four-Stroke Engine-
A four-stroke engine is more reliable than a two-stroke engine. In this type of engine, the power stroke is produced by the 4-time revolution of the crankshaft. The strokes are- Suction, Compression, Power, and exhaust. The crankshaft revolves 720 degrees to produce one single power stroke.
Differences-
The differences between four-stroke and two-stroke are as follows:
| Sl. No | Four-stroke | Two-stroke |
|---|---|---|
| 01 | One working stroke for every two revolutions of the crankshaft. | One working stroke for each revolution of the crankshaft. |
| 02 | The turning moment on the crankshaft is not even due to one working stroke for every two revolutions of the crankshaft. Hence heavy flywheel is required and the engine runs unbalanced. | The turning moment on the crankshaft is more even due to one working stroke for each revolution of the crankshaft. Hence lighter flywheel is required and the engine runs balanced. |
| 03 | The engine is heavy. | The engine is light. |
| 04 | The Engine design is complicated. | The Engine design is simple. |
| 05 | More cost. | Less cost. |
| 06 | Less mechanical efficiency due to more friction on many parts. | More mechanical efficiency due to less friction on a few parts. |
| 07 | More output due to full fresh charge intake and full burnt gases exhaust. | Less output due to mixing of fresh charge with the burnt gases. |
| 08 | The engine runs cooler. | The engine runs hotter. |
| 09 | The engine is water-cooled or coolant cool. | The engine is air cooled |
| 10 | Less fuel consumption and full burning of fuel. | More fuel consumption and the fresh charge are mixed with exhaust gases. |
| 11 | The engine requires more space. | The engine requires less space. |
| 12 | Complicated lubricating system. | Simple lubricating system. |
| 13 | The engine creates less noise. | The engine creates more noise. |
| 14 | Used in cars, buses, and trucks. | Used in mopeds, Scooters, and motorcycles. |
| 15 | More thermal efficiency. | Less thermal efficiency. |
| 16 | Less wear and tear of moving parts. | More wear and tear of moving parts. |