Lesson 1/Learning Event 1
of the chamber from under the plunger. This closes the ball check valve, and the trapped oil lifts the plunger
opening the engine valve. When the lobe moves out from under the tappet, any slight loss of oil from under
the plunger is replaced by oil pressure from the lubricating system.
FIGURE 36. CAMSHAFT DRIVES.
There are two common methods of turning the camshafts of multi-cylinder engines in wheeled vehicles. One
is with gears as you studied on the basic one-cylinder engine. In the other method, two sprockets and a timing
chain or belt, something like a bicycle drive, are used. A timing chain or belt is most likely to be used when
the crankshaft and camshaft are not very close together