Hydraulic Valve Lifters

Adjust rocker arm nuts to eliminate lash. This is done when the valve lifter is on the base of circle of the camshaft

Remove distributor cap and crank the engine until the distributor rotor points to #1 cylinder terminal with points open.

Note the preload and setting instructions are for factory hydraulic lifters and camshaft. Aftermarket manufacturers may have different lash suggestions/requirements. Initial setting of lifters at #1 & #6

Chevrolet 6-Cylinder Engine

Rotate crankshaft to number 1 firing position:
Intake numbers 1, 2, & 4 and exhaust numbers 1, 3, & 5.

Turn adjusting nut until all lash is removed. When all play has been removed, turn adjusting nut one more turn. This is place the lifter plunger in the center of its travel. When the above valve lifters have been adjusted, rotate the crankshaft until cylinder #6 is in firing position.

Repeat adjustment for intake numbers 3, 5, & 6 as well as exhaust numbers, 2, 4, & 6.

Chevrolet V8 Engine

Rotate crankshaft to number 1 firing position:

Intake numbers 1, 2, 5, & 7 as well as exhaust numbers 1, 2, 4, & 8.

Turn adjusting nut until all lash is removed. When all play has been removed, turn adjusting nut one more turn. This will place the lifter plunger in the center of its travel. When above valves have been adjusted, rotate crankshaft until cylinder #6 is in firing position.

Rotate crankshaft to number 6 firing position.

Number 6 firing position:
Intake numbers 3, 4, 6, & 8 as well as exhaust numbers 2, 5, 6, & 7.

Repeat adjustment.

With Engine Running

Readjust the lifters with the engine running and warmed to operating temperature.

1. Remove rocker arm covers and gaskets.

2. Place oil deflector clips on rocker arms.

3. With engine running at idle, back off rocker arm nut until it starts to clatter.

4. Turn rocker arm nut down until clatter stops; this is zero lash.

5. Tighten rocker arm nut one-quarter turn and pause ten seconds. Repeat additional quarter turns at ten second pauses until the rocker arm nut has been tightened one full turn from zero lash.

6. Repeat steps 3, 4, and 5 for all rocker arm nuts.

Mechanical Valve Lifters

Mechanical lifters can initially be set much like hydraulic lifters with the difference being the initial valve lash required by the camshaft manufacturer. Hydraulic lifters are set to zero lash plus one turn where mechanical lifters are set with a feeler gauge to the camshaft's recommended clearance.

Number 1 firing position:
Intake numbers 2 & 7 and Exhaust numbers 4 & 8.

Turn crankshaft one-half revolution clockwise:
Intake numbers 1 & 8 and Exhaust numbers 3 & 6.

Turn crankshaft one-half revolution clockwise to number 6 firing position:
Intake numbers 3 & 4 and Exhaust numbers 5 & 7.

Turn crankshaft one-half revolution clockwise:
Intake numbers 5 & 6 and Exhaust numbers 1 & 2.

Warm the engine to normal operating temperature and reset all clearances with engine running for hydraulic lifters or to set mechanical lifter valve lash to camshaft manufacturer's specifications.

Rocker arm oil clips come in several configurations. Their goal is redirect the oil stream from the push rod. Note: If you are using aftermarket roller rocker arms with a square design, these may not work.

A feeler gauge set has numerous blades of varying thickness used to set the correct valve lash on a mechanical lifter camshaft.