The compression ratio is an indicator of the engine’s fuel efficiency. A gasoline engine’s compression ratio can range from 6:1 to 10:1. The ignition (combustion) event occurs as soon as the charge is ignited and is accelerated by a chemical reaction to release heat energy.

The intake valve is opened as an ambient pressure pushes air-fuel mixture into the cylinder through it.

During an operating cycle, a crankshaft must cycle twice as fast (720 degrees). In the case of the piston, the cylinder must be filled twice during the operating cycle. To produce one pulse of power, the crankshaft must rotate twice, and each piston must rotate twice as well.Īn internal combustion engine with four distinct pistons strokes (intake, compression, power, and exhaust) is known as a four-stroke cycle engine. All cars and light trucks now have four- stroke piston engines, regardless of whether they burn gasoline or diesel.