A. You could. However two things would happen. First you would need to adjust can timing manually, which can be cumbersome and error-prone. Secondly, you would risk damaging the engine or causing it to run incorrectly. Lost timing affects engine performance. If your car uses an interference engine, the valves share the space above the cylinder bore with the piston but at different times. With the timing off, these two parts could collide and cause severe engine damage. A timing tool kit helps you avoid all these problems.