146 Auto Engine Repair Copyright by Goodheart-Willcox Co., Inc. Intake manifold Cam gears Timing chain Cylinder head Cylinder Piston Oil pickup Oil pan Rod Cylinder block Connecting rod Cams Valves Figure 6-42. This is a front view of a dual overhead camshaft engine. Notice the long timing chains used to spin the camshaft sprockets at one-half of the crankshaft speed. (Cadillac) Combustion chamber Intake valve Camshafts Exhaust valve Oil filter Piston Connecting rod Crankshaft Oil pan Figure 6-43. This is a DOHC V-6 engine. Note the parts. (Lexus)