1. Air Intake and Compression:
* Air Intake: The engine draws in air through the intake manifold.
* Compression: The piston moves upwards, compressing the air inside the cylinder. This increases the air's temperature and pressure.
2. Fuel Injection:
* Injector: A fuel injector sprays a precise amount of petrol into the combustion chamber, usually just before or during the compression stroke.
3. Spark Ignition:
* Spark Plug: A spark plug, located in the combustion chamber, generates a high-voltage spark at the right moment.
* Ignition: The spark ignites the air-fuel mixture, triggering a rapid chemical reaction called combustion.
4. Combustion and Expansion:
* Rapid Burning: The ignited fuel burns very quickly, creating a sudden increase in pressure and temperature.
* Expansion: The expanding gases push the piston downwards, converting chemical energy into mechanical energy.
5. Exhaust:
* Exhaust Valve: After the combustion cycle, the exhaust valve opens, allowing the burnt gases to escape into the exhaust system.
Key Factors for Ignition:
* Compression Ratio: The ratio of the cylinder volume at the bottom of the stroke to the volume at the top of the stroke. Higher compression ratios increase temperature and pressure, making ignition easier.
* Spark Timing: The precise moment the spark plug fires is critical for optimal combustion. This timing is controlled by the engine's electronic control unit (ECU).
* Fuel-Air Mixture: The ratio of fuel to air must be within a specific range for proper combustion.
Let me know if you'd like to dive deeper into any specific aspect of this process!
