Vauxhall Workshop Service and Repair Manuals

Valve Timing, Check

Timing is correct if piston of cylinder 1 is just before TDC and valves of cylinder 4 are crossing.

On OHC engines, valve timing is checked at 10° on crankshaft before TDC, (5° on camshaft before TDC).

This is achieved if

marking on camshaft sprocket is opposite marking on housing (OHC engines) or crankshaft sprocket (OHV engines) and pointer (OHC engines) or boss (OHV engines) points to notch on belt pulley and distributor rotor is at mark on distributor housing.