Two-Stroke Engine
An internal-combustion engine that has one power stroke per revolution.
Animation of a two-stroke glow plug engine.
The sequence of events is:
- Fuel air explosion
- Piston is driven down - power stroke
- As the piston moves towards the bottom of it’s stroke, the exhaust port is uncovered
- Exhaust gases are driven out
- When the piston has bottomed out, the intake port is uncovered
- New fuel and air enters and is ready for compression and combustion.
- As the fuel mixture is being compressed a vacuum is created in the crankcase.
- The vacuum opens a reed valve and sucks air/fuel/oil from the carburetor into the crankcase.
Advantages
- Simplified construction
- Great power to weight ratio - fire once every revolution for a significant power boost
Disadvantages
- The engines do not last as long due to poor lubrication.
- Have to mix lubrication oil with the fuel
- Do not use fuel efficiently.
- Two-stroke engines produce a lot of pollution.
See also: Engine, Four-Stroke Engine, Petrol Engine.
Subjects: Automotive Engines