What is a common effect of improper valve timing in an engine?

Improper valve timing in an engine can significantly disrupt the timing of the intake and exhaust processes, leading to decreased efficiency. Efficiency in an engine is often measured by how well it converts fuel into useful work. When the valves do not open and close at the optimal times, it can result in several issues, such as incomplete combustion, backflow of exhaust gases into the intake, or insufficient fresh air entering the combustion chamber.

When these issues occur, the engine struggles to run effectively. This can cause a loss of performance since the engine cannot generate the required power output with the least amount of fuel. Therefore, decreased efficiency is a direct consequence of improper valve timing, as it fails to maximize the engine's operation cycle, leading to more unutilized fuel and energy. By maintaining proper valve timing, the engine can operate at its designed efficiency, optimizing fuel utilization and performance.