LNG Combustion

What Creates the Blast That Pushes a Piston in a Car Engine?

In a gasoline-powered car engine, four main elements work together to create the combustion that pushes the piston downward and produces power:

1. Air (Oxygen)
   • The engine draws air into the cylinder through the intake system.
   • Oxygen in the air is essential for burning the fuel.
2. Fuel
   • Gasoline is injected into the engine cylinder or intake port.
   • The fuel mixes with the incoming air to form a combustible mixture.
3. Compression
   • The piston moves upward and compresses the air-fuel mixture.
   • Compression increases pressure and temperature, making combustion more efficient and powerful.
4. Spark (Ignition)
   • A spark plug generates an electric spark near the top of the compression stroke.
   • The spark ignites the compressed air-fuel mixture.

The ignition creates rapidly expanding hot gases. This sudden increase in pressure pushes the piston downward, producing the engine's power stroke.

The Four-Stroke Engine Cycle

1. Intake Stroke – Air and fuel enter the cylinder.
2. Compression Stroke – The piston compresses the mixture.
3. Power Stroke – The spark ignites the mixture, forcing the piston downward.
4. Exhaust Stroke – Burned gases are expelled from the cylinder.

What About Diesel Engines?

Diesel engines also require air, fuel, and compression, but they normally do not use spark plugs for combustion.

• Air is compressed to a very high pressure.
• The compressed air becomes extremely hot.
• When diesel fuel is injected, it ignites automatically due to the heat.

Gasoline Engine Formula:

Air + Fuel + Compression + Spark = Combustion → Expanding Gases → Piston Movement → Engine Power