How to Set the Timing Chain for a 350 Motor

A 350 engine uses a single timing chain. Two timing gears attach the chain to the camshaft in the middle of the engine and the crankshaft at the top of the engine. After some time, the chain will stretch and lose its effectiveness in running the engine. This can lead to backfiring. Alignment of the gear marks is key to setting the new chain. Otherwise, the installation is fairly simple and can be completed in a few steps.

• 1

  Look for the "O" marks on the faces of the crankshaft and the camshaft. These marks are located on each end of the timing chain. The crankshaft is at the bottom of the engine, and the camshaft is in the middle of the engine. Both are easily identifiable on each end of the timing chain and are cylindrical with a variety of different-sized, thick metal pins on them.

• 2

  Align the "O" marks of the upper and lower timing gears by rotating the bolt at the center of the crankshaft with an adjustable wrench. The camshaft "O" should point upward. The crankshaft "O" should point downward.

• 3

  Unscrew the three bolts located on the face of the upper timing gear with the adjustable wrench.

• 4

  Remove the upper timing gear and the timing chain by hand.

• 5

  Insert the new timing chain into place by placing one end of the chain around the upper timing gear and the other end around the lower timing gear.

• 6

  Place the upper gear back onto the camshaft. Tighten the three bolts to between 15 and 20 foot-pounds with a torque wrench.