What status does the intake valve have during the intake stroke?

During the intake stroke of an internal combustion engine, the intake valve is opened. This is critical because the purpose of the intake stroke is to allow air (and fuel in the case of gasoline engines) to enter the combustion chamber. As the piston moves down in the cylinder, a vacuum is created, which helps to draw in the air-fuel mixture through the opened intake valve.

The timing of the valve being opened is synchronized with the movement of the piston, ensuring that maximum air enters the cylinder to prepare for the subsequent compression stroke. If the intake valve were closed during this phase, no air would enter the cylinder, preventing the engine from running efficiently or potentially causing it to stall.

Thus, having the intake valve opened during the intake stroke is essential for the engine's operation. It directly contributes to the engine's ability to intake the proper amount of air and fuel, leading to effective combustion. This is a fundamental concept in understanding engine operation and is crucial for tasks related to small engines in agricultural and mechanical settings.