An engine is a series of moving parts that work in unison to produce power. If the engine’s components are not synchronized, the engine’s power output will be substantially diminished and the vehicle’s gas mileage will suffer. This synchronization is typically referred to as “timing,” and is checked with a timing light and adjusted at the distributor. Chevrolet V8 engines are fairly simple to time, particularly considering that the timing points are at the front of the engine at the harmonic balancer.
Locate and mark the correct timing point. Surrounding the outer edge of the harmonic balancer are several lines and numbers. Each line represents a number of degrees out of a 360-degree circle. The line to be marked varies, depending on the engine, and can be found by referencing the engine’s specification’s manual. Scribe the appropriate mark on the harmonic balancer with a piece of chalk.
Mark the tip of the timing pointer. The timing pointer is a small metal piece just above the harmonic balancer. The piece tapers down to a tip. Mark this tip with a piece of chalk.
Attach a timing light to the battery and to the No. 1 spark plug wire. A timing light consists of a timing gun and three cords. Attach the cord with the black alligator clip to the negative battery terminal. Attach the cord with the red alligator clip to the positive battery terminal. The final cord clips anywhere along the spark plug cable for the number one spark plug. On the Chevrolet V8, the number one spark plug wire is at the front of the engine, on the driver’s side.
Disconnect the vacuum hose from the distributor, if applicable. Older Chevrolets feature a saucer-shaped vacuum canister on the side of the distributor. A small rubber hose slides over a metal fitting in the center of the canister. Pull the hose off of the vacuum canister, then plug the hose with a screw or golf tee.
Loosen the bolt in the center of the distributor’s hold-down clamp at the base of the distributor with a wrench.
Ensure that the three wires from the timing light are free of the fan blades and engine belts, then turn the engine on.
Pull the trigger on the timing light and point the light at the harmonic balancer. As the timing light flashes, the light will reflect off of the two chalk marks. The engine is “timed” when these two chalk marks align. Twist the distributor until the marks align, then turn the engine off.
Disconnect the three timing light wires, tighten the distributor’s hold-down clamp with a wrench, then plug the vacuum hose into the vacuum canister on the distributor.
