Detailed Explanations of 4-Stroke and 2-Stroke Engines

4-Stroke Engine:

Working Principle:

Completes a power cycle in four strokes: Intake, Compression, Power, and Exhaust. The piston moves up and down twice, while the crankshaft completes two rotations in one cycle. Utilizes separate strokes for intake and exhaust, making it more efficient and cleaner.

Applications:

Used in cars, trucks, buses, and power generators due to higher efficiency and durability.

Pros:

• Higher fuel efficiency
• Produces lower emissions
• Durable with longer maintenance intervals

Cons:

• More complex design with additional components (e.g., valves, camshaft)
• Heavier and larger
• Higher manufacturing and repair costs

2-Stroke Engine:

Working Principle:

Completes a power cycle in two strokes: Compression-Power and Exhaust-Intake. The piston moves up and down once, while the crankshaft completes one rotation in one cycle. Combines intake and exhaust strokes, resulting in faster operation but less efficiency.

Applications:

Found in motorcycles, scooters, chainsaws, outboard motors, and small power tools where compactness and simplicity are key.

Pros:

• Simpler design with fewer components.
• Lighter and more compact
• Higher power-to-weight ratio, making it suitable for portable devices

Cons:

• Less fuel-efficient due to fuel loss during the intake-exhaust overlap
• Produces higher emissions
• Requires more frequent maintenance and has a shorter lifespan