Hydraulic Valve Lifter Adjustment

Repeated valve (seat and face) reconditioning operations will decrease valve stem to rocker arm clearance to point that if compensation is not made, valve lifters will cease to function. To compensate for any dimensional changes in valve mechanism, a 0.060" shorter or a 0.060" longer replacement push rod is available. To determine whether or not a longer or shorter push rod is necessary, clearance between rocker arm and valve stem must be checked. Use suitable tool and slowly collapse valve lifter until plunger is bottomed. Hold lifter down while checking clearance. Procedure for checking valve clearance is as follows:

1. Rotate crankshaft until No. 1 piston is at TDC (point "A" in Fig 1) after compression stroke as indicated by timing mark on crankshaft damper and pointer. Make a chalk mark on damper 180° (point "B") from TDC mark. Make a chalk mark on damper 90° (point "C") clockwise from TDC mark.
   Fig 1: Different Positions To Place Crankshaft Damper When Making Hydraulic Valve Lifter Adjustment

   Courtesy of FORD MOTOR CO.
2. With damper at point "A", check following valve clearances with specifications:

   302" - Intake No. 1, 7, 8. Exhaust No. 1, 5, 4.

   Others - Intake No. 1, 4, 8. Exhaust No. 1, 3, 7.

3. Rotate crankshaft 180° clockwise from point "A" so that point "B" is opposite pointer. Check following valve clearances:

   302" - Intake No. 4, 5. Exhaust No. 2, 6.

   Others - Intake No. 3, 7. Exhaust No. 2, 6.

4. Rotate crankshaft 270° clockwise from point "B" so point "C" is opposite pointer. Check following valve clearances:

   302" - Intake No. 2, 3, 6. Exhaust No. 3, 7, 8.

   Others - Intake No. 2, 5, 6. Exhaust No. 4, 5, 8.

   VALVE CLEARANCES
   
   

   Application	Desired	Allowable
   302" & 351" W	.096-.168"	.071.193"
   351" M & 400"	.125-.175"	.100-.200"

5. If clearance is less than specified, install shorter push rods; if greater than specified, install longer push rods.