What is the primary purpose of valve springs in an aircraft reciprocating engine?

The primary purpose of valve springs in an aircraft reciprocating engine is to control the timing of the valve opening and closing. Valve springs ensure that the valves are held closed when they are not actuated by the camshaft and are pushed open at the appropriate times during the engine cycle. This precise control is critical for maintaining the engine’s efficiency and performance, as it directly influences the timing of the intake and exhaust cycles.

When the camshaft rotates, it pushes against the rocker arm or directly against the valve, compressing the spring and allowing the valve to open. Once the cam's profile has moved past the high point, the spring forces the valve back to its closed position, sealing the combustion chamber and maintaining optimal compression.

While the absorption of vibrations can be a secondary benefit of the springs due to their construction and material, it is not their primary purpose. Similarly, maintaining proper valve clearance is important for engine operation, but it is not the role of valve springs alone; clearances are adjusted not only by the springs but also by the rocker arm and valve lifter design. Preventing valve float at high speeds is a related concern, as insufficient spring tension can lead to this phenomenon. However, the overarching function of valve springs remains their essential role in