FENDER GP 4827004 - Caterpillar

is a camshaft group for each side of the engine.The camshafts are made from identical camshaft segments, journals, spacers and a drive end. Each camshaft segment has three lobes. The camshaft segments are replaceable at each cylinder through access holes in the cylinder block. The left camshaft for the 3618 Engine is supported by 10 bearings and the right camshaft for the 3618 Engine is supported by 11 bearings. A thrust plate at the rear of each camshaft controls end play.As the camshaft turns, each lobe moves a lifter assembly. There are three lifter assemblies for each cylinder. Each outside lifter assembly moves a pushrod and a valve (inlet or exhaust). The center lifter assembly moves a pushrod that operates the fuel injector.Each camshaft must be in time with the crankshaft and with each other. The relation of the camshaft lobes to the crankshaft position causes the valves and fuel injectors in each cylinder to operate at the correct time. The timing relationship of the camshafts and crankshaft is established from the No. 1 cylinder. The timing is set from the Top Center position on the compression stroke. Timing pins are provided for the camshafts and the crankshaft in order to establish the Top Center position of the No. 1 cylinder.