The exhaust camshaft is driven directly
by the chain and transmits motion to the inlet camshaft via a pair
of straight toothed gears.The exhaust camshaft also drives the high-pressure
pump, while the inlet camshaft drives the vacuum unit.
TAPPETS
There is a hydraulic tappet for each valve
activated by a rocker arm, in turn, moved by the camshaft.The rocker arms are designed to prevent
serious damage to the other engine components if the timing chain
breaks or comes off; in effect, on account of their special design
the absorb the stresses caused through the contact between the valves
and the pistons.
