What is the function of the intake valves?

The function of the intake valves is to control the entry of the fuel/air mixture into the combustion chambers. During the engine’s intake stroke, these valves open to allow the precisely metered mixture of fuel and air to flow into the combustion chamber, where it is then compressed and ignited to produce power. This precise control is crucial for efficient engine performance, ensuring that the correct amount of the mixture is introduced, which affects combustion efficiency, power output, and emissions.

Other responses relate to aspects of engine operation but do not accurately describe the primary role of the intake valves. For instance, maintaining constant engine speed in response to load demands is associated more with the throttle or Engine Control Unit (ECU) adjustments rather than directly with the function of the intake valves. Similarly, regulating air flow pertains more to components like the throttle body or carburetor, which manage the air-fuel ratio but operate independently of the valve mechanism. Creating a vacuum to draw air in is a function of engine dynamics but does not encapsulate the specific role of the intake valves. Thus, option C best describes their critical function in engine operation.