Arrange the following events in the correct chronological order to describe a single complete cycle of a standard four-stroke internal combustion engine, beginning with the intake of the fuel mixture.
- 1The intake valve opens as the piston moves downward, drawing the air-fuel mixture into the cylinder.
- 2Both valves remain closed while the piston moves upward, squeezing the air-fuel mixture into a smaller volume.
- 3A spark ignites the compressed mixture, causing a rapid expansion that forces the piston downward.
- 4The exhaust valve opens as the piston moves upward, expelling the burned gases from the cylinder.
Answer
The correct sequence is: 1) Intake valve opens / piston down, 2) Valves closed / piston up (Compression), 3) Spark ignites / piston down (Power), 4) Exhaust valve opens / piston up.
A standard internal combustion engine operates on a four-stroke cycle: Intake, Compression, Power, and Exhaust. First, the piston moves down to draw in air and fuel. Second, it moves up with valves closed to compress the mixture. Third, the spark plug ignites the mixture, causing a rapid expansion that forces the piston down to perform work. Finally, the piston moves up with the exhaust valve open to expel the burned gases, completing the cycle.
Step-by-Step Solution
Key Concept
Four-Stroke Engine Operating Cycle
Estimated Time:1m 0s