Timing Components: Testing and Inspection

CHECKING VALVE TIMING
1. Remove all spark plugs and left cylinder head cover.

2. Rotate crankshaft until cylinder #1 is a Top Dead Center (TDC).

3. Install a dial indicator in the spark plug hole for cylinder #1 and set the piston at Top Dead Center (TDC) in valve overlap (with the intake valve starting to open and the exhaust valve just closing).

4. Install a degree wheel on the crankshaft. Fabricate a pointer made of wire and set it up so the 0° mark on the degree wheel is aligned with the pointer.

5. Remove the dial indicator from the spark plug hole and install the dial indicator over the #1 cylinder intake valve retainer with the dial indicator shaft parallel to the valve stem.

6. Rotate the crankshaft clockwise until the dial indicator reads maximum lift. Back up the crank-shaft until the dial indicator has dropped at least 0.050" from maximum lift.

7. Rotate the crankshaft slowly forward until the dial indicator reads 0.025" less than maximum lift. Record the degrees after TDC. If the crank is accidentally rotated past the point of 0.025" lift, rotate backwards until the dial indicator reads at least 0.050" and rotate slowly clockwise again until the reading of 0.025" is reached.

8. Rotate the crankshaft clockwise past the point of maximum valve lift and stop as the dial indicator reads exactly 0.025" less than maximum valve lift. Record the degrees after TDC. Once again, if the crankshaft is rotated past the 0.025" drop point, back up to TDC and rotate slowly to the 0.025" drop point.

9. Add the two numbers together and then divide by two. The result is the centerline of the maximum intake camshaft lobe lift.

10. This number must be 121 degrees ±1 degrees. If the reading is out of specification, repeat the procedure to verify the result.

11. If the number of degrees is still out of specification, the timing chain case cover will have to be removed and the camshaft timing corrected to specification.