What component must be timed with the crankshaft to ensure proper operation of the valves?

The component that must be timed with the crankshaft to ensure proper operation of the valves is the camshaft. The camshaft is responsible for opening and closing the engine's valves in synchronization with the movement of the pistons, which are connected to the crankshaft. Proper timing ensures that the valves open and close at the right moments during the engine cycle, allowing for efficient intake of air and fuel and the expulsion of exhaust gases.

The camshaft has lobes that push against the valves which, when timed correctly with the crankshaft's position, allows for optimal engine performance. If the camshaft is not properly aligned with the crankshaft, it can lead to valve timing issues, which can cause poor engine performance, misfires, or even engine damage.

Other components mentioned, like the piston, flywheel, and fuel injector, do not directly control the timing of the valves relative to the crankshaft. While they are critical to engine operation, they do not play a role in managing valve timing in the same way that the camshaft does.