Many engine builders have experimented with cam timing in their engines. While it is well known that setting a little more advance into an engine’s timing helps with high-speed horsepower, few people understand the benefits of retarding the cam timing in a performance engine. Retarding the timing allows the engine to perform in the bottom to mid-range end of its power band. This type of timing is very beneficial to power boats and four-wheel drive vehicles that will not operate at wide-open throttle.
Place the vehicle on a flat surface and apply the parking brake. Don safety glasses. Open the hood and remove the battery cable from the negative side of the battery by loosening the bolt with a wrench. Place the cable where it cannot contact the battery post.
Drain the radiator. Place a bucket or pan under the radiator petcock and open the petcock by turning it with your hand. Collect the coolant in the pan and set it to the side. Remove the radiator by loosening the hose clamps with a screwdriver and pulling them off of the water pump. Loosen the radiator retaining bolts with a wrench and lift the radiator out of the vehicle. On some vehicles, it may be necessary to remove the fan shroud by loosening its retaining bolts with a wrench before you can remove the radiator.
Remove the water pump. Loosen the retaining bolts from the water pump with a wrench and pull the pump free. Set the fan belt off to the side and out of the way.
Loosen the bolt from the harmonic balancer with a socket wrench. Using the gear puller, remove the balancer.
Loosen the bolts from the timing cover with a wrench and pull the cover off of the engine block. This may require prying it off with a screwdriver.
Remove the timing set. Loosen the bolts holding the top timing gear to the cam with a wrench and remove the gear. Slide the lower timing gear along with the timing chain off of the crankshaft snout. Discard these pieces and use a new timing set.
Decide how much you wish to retard the camshaft. This will depend on your intended purpose for the engine, tire size, gear ratio, cam size, RPM range, etc. The retard bushings come in 0, 1, 2, 3 and 4 degrees. Place a drill bit into the drill motor and drill out the hole that goes over the cam index stud (this is a different location for every make of engine) to the specified diameter of the retard bushing. Place the appropriate bushing into the hole and lock in place by pining it (making a notch between the bushing and the timing gear) with a chisel and hammer. Slide the bottom gear of the new timing set onto the crankshaft snout. Place the new timing chain over the bottom gear and insert the top gear into the chain. Place the top gear with the retard bushing onto the camshaft and replace the bolts. Tighten with a wrench.
Reassemble the vehicle. Reassemble in the reverse order, top off the radiator with coolant and start the engine. Set the timing with a timing light to your vehicle's manufacturer’s specifications.
