WIS Document: 7839

| | Valve-gear timing When the pistons in cylinders No. 1 and No. 4 are at top dead centre, the mark on the crankshaft pulley should be in line with the mark on the timing cover. Alternatively, the 0 mark on the flywheel/driver disc should be in line with the mark on the end plate. When the timing marks on the camshafts are in line with those on the bearing caps, the inlet and exhaust valves for the No. 1 cylinder are closed. As the valves open, they extend beyond the face of the cylinder head and into the zone where the pistons change direction. As will be realized, if the setting of the crankshaft and valve gear is altered, the valves and other vital parts of the engine will be damaged.