Here's why:
* Power Stroke: This is the stage where the burning fuel expands and pushes the piston down, converting chemical energy into mechanical energy.
* Valve Timing: For maximum efficiency, the intake valve closes shortly after the piston begins its upward stroke (compression) and the exhaust valve opens just before the end of the power stroke.
* Closed Valves: During most of the power stroke, both valves are closed to create a sealed combustion chamber. This ensures the pressure from the burning fuel acts directly on the piston, maximizing power output.
Let me know if you'd like a more detailed explanation of the four-stroke cycle!
