What is a potential consequence of running an engine with improperly set valve timing?

Running an engine with improperly set valve timing can lead to lower volumetric efficiency because the timing of the valve openings and closings plays a critical role in the engine's ability to fill its cylinders with air (or air-fuel mixture) during the intake stroke and effectively expel exhaust gases during the exhaust stroke. When the valves are out of sync, it can result in a situation where the intake valve closes too early or the exhaust valve opens too late. This misalignment disrupts the optimal flow of gases in and out of the cylinders, effectively reducing the volume of air or fuel mixture available for combustion, leading to a decrease in power output. Consequently, the engine struggles to perform efficiently, which can impact various aspects, including power, torque, and overall engine performance.