Hydraulically Operated Valves
On engines
with hydraulic valve lifters, it is not necessary to adjust the valve periodically. The
engine lubrication system supplies a flow of oil to the lifters at all times. These
hydraulic lifters operate at zero clearance and compensate for changes in engine
temperature, adapt automatically for minor wear at various points, and provide ideal valve
timing.
To adjust
hydraulic lifters with the engine off, turn the crankshaft until the lifter is on the
camshaft base circle (not the lobe). The valve must be fully closed.
Loosen the
adjusting nut until you can wiggle the pushrod up and down. Then slowly tighten the rocker
until all play is out of the valve train (cannot wiggle pushrod). Repeat the adjusting
procedure on the other rockers.
To adjust
hydraulic lifters with the engine running, install a special oil shroud or some other
device for catching oil spray off the rocker. Start and run the engine until it reaches
operating temperature. Tighten all rockers until they are quiet. One at a time, loosen a
rocker until it clatters. Then tighten the rocker slowly until it quiets down. This is
zero valve lash. |