Advantages And Disadvantages Of Two-Stroke Engine Over Four-Stroke Engine
Advantages
- Simple mechanism.
- Easy to start.
- It gives one power stroke per revolution of the crankshaft. High power to weight ratio and significant power boost.
- It has no valves, so complicated valve actuating mechanism not required.
- It is light weight, 30% lighter than the 4-stroke engine.
- It has few moving parts, so compact and simple construction.
- No oil sump for lubrication. Petroil is used for lubrication so it can be used in all positions.
- Low maintenance cost.
- The work required to come over the friction of suction and exhaust is saved.
- As there is a power stroke in every revolution, the turning moment is uniform. Light flywheels are required.
- Incomplete combustion, carbon deposit on the piston head and exhaust port.
- Unstable idling.
- Scavenging problems.
- Less efficient in terms of fuel economy due to part of the unburned charge is rejected during transfer phase.
- More wear and fragile than the four-stroke engine. Shorter life span.
- They are liable to cause high consumption of lubricating oil.
- Worst hydrocarbon emission rate. High polluting.
- High vibration and noisy operation.
- Less thermal and volumetric efficiency.
- Narrow power band compared to a four-stroke engine.
- Comparison between SI engine and CI engine
- Difference between two-stroke and four-stroke engine