Two stroke engine
In this engine, the exhaust and intake take place simultaneously with the power stroke.
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Four stroke engine
There are four operations in a complete power cycle of a four stroke engine.
- Intake stroke: In this stroke the air required for combustion is directed inside the piston with the help of an intake valve. The piston travels down in this operation
- Compressions stroke: The inlet valve closes and the piston starts to move up. When the compression ratio is appropriate, fuel is injected and the spark plug produces a spark that induces combustion.
- Combustion stroke: The force of combustion forces the piston down and it helps turn the crankshaft.
- Exhaust stroke: The piston moves up again and clears the space above it of any exhaust gases.
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