Position the crankshaft to ensure that the timing mark on the timing tab on the timing chain cover aligns with the 0 mark on the timing scale.
This positions the cylinder number one piston at Top Dead Center (TDC) on the compression stroke.
In this position the distributor rotor will be aligned with the number 1 spark plug wire terminal on the distributor cap.
Chain Installation with Correct Timing Marks Alignment
With cylinder number 1 at TDC, the timing marks on the crankshaft sprocket and camshaft sprocket must align.
The camshaft sprocket has a larger diameter than the crankshaft sprocket and has marks on the outer perimeter.
For the correct alignment of the timing chain:
- Install the timing chain over the camshaft sprocket so that the timing mark on the camshaft sprocket aligns with the O mark on the timing scale on the timing cover.
- Now rotate the crankshaft sprocket so the timing mark on the sprocket aligns with the 0 mark on the timing scale.
- Fit the timing chain around the crankshaft sprocket and the camshaft sprocket.
Chevy 350 Timing Chain Installation Tips
- When fitting the timing chain, the engine should be in gear (transmission in Park or Neutral) or the crankshaft and camshaft should be locked to prevent the engine from rotating.
- The timing chain must be tensioned correctly. The tensioner is located on the front of the engine and is actuated by the oil pressure when the engine is running.
- If the timing chain is too loose, it can skip over the teeth on the camshaft and camshaft sprockets, causing the engine to run poorly.
- If the timing chain is too tight, it can put excessive strain on the engine's components and lead to premature failure.
