Chevrolet big-block V8 engines were introduced in the late 1950s and have powered many medium-duty trucks and heavy car models ever since. The timing belts on these engines ensure that the truck runs smoothly, and since they stretch with age, they can start jumping gear teeth. Setting the timing when replacing a big-block engine’s aging timing belt requires interaction with the entire timing system.
The timing system in a big-block engine consists of a crankshaft connected by chain to a camshaft. The system controls the synchronized lifting, or opening, and closing of the various intake and exhaust valves along the distributor. The chain, also known as the timing belt, controls this synchronization between the crankshaft component and the fuel injection system via a system of gear pulleys. The timing system also includes two seals for the tensioner and crankshaft oil vessel. All of these parts are sized differently for certain models, and the most noticeable difference is the type and width of gear teeth present.