Timing Belts
Timing Belt Operation - Diagrams and Animations
To fully understand the importance of a timing belt one must have a basic knowledge of the internal working parts of an engine. We will start with terms. Camshafts, crankshaft, piston, intake and exhaust valves. See diagram 1. The camshaft and crankshaft both rotate, the camshafts rotate once for every two rotations of the crankshaft. The pistons are attached to the crankshaft and move up and down inside the cylinders. The camshafts open and close the intake and exhaust valves. The job of the timing belt is to keep the motions of the of all these parts in synchronization with each other.
The animation in Diagram 2 shows the relative movements of the internal parts of the engine as seen from the front. The drawing below on the right shows a side view of the engine with the external timing belt connecting the crankshaft and camshafts. This belt is a toothed rubber belt which must be changed periodically. If the belt breaks the crankshaft and camshafts, which operate the valves, will get out of synchronization with each other causing the pistons and valves to collide and resulting in major engine damage.
The animation in Diagram 4 shows what happens when the timing belt breaks. The crankshaft will keep turning until the car has almost come to a stop because it is connected with the wheels of the car. The camshafts will continue to rotate a few turns as they slow to a stop. As the two get out of synchronization the valves that are open will be hit by the moving pistons. This always damages the valves and sometimes the pistons or even the head. Never cheap!
Print this page and bring it to receive 5% off the cost of your scheduled timing belt replacement.
Coupon does not apply to repairing damaged engines from a broken timing belt.
Coupon does not apply to repairing damaged engines from a broken timing belt.