Timing Components: Testing and Inspection
CHECKING VALVE TIMING
^ When the pistons in No. 1 and No. 4 cylinders are at top dead center, the 0° mark on the flywheel must be in line with the timing mark on the clutch cover (or end plate if the clutch cover has been removed).
^ When the timing marks on the camshafts are in line with those on the bearing caps, both the inlet and the exhaust valves for No. 1 and No. 4 cylinders are closed.
^ As the valves open, they extend beyond the face of the cylinder head and into the zone in which the pistons move (combustion chamber).
CAUTION: If the setting of the crankshaft and valve gear is altered, the valves may collide with the pistons, with ensuing damage to the valves and other vital components.