Valve Clearance

The valve arrangement of the LH bank is E-I-E-I-E-I-E-I and of the RH bank is I-E-I-E-I-E-I-E.

A 1.52mm (0.060-inch) shorter push rod (6565) or a 1.52mm (0.060 inch) longer push rod is available for service to provide a means of compensating for dimensional changes in the valve mechanism. Refer to the Master Parts List or the Specifications listed for the pertinent color code.

Valve stem-to-rocker arm clearance should be within specification with the hydraulic valve tappet (6500) completely collapsed. Repeated valve reconditioning operations (valve and/or valve seat refacing) will decrease the clearance to the point that, if there is not compensation, the hydraulic valve tappet will cease to function and the valve will be held open.

The valve stem-to-rocker arm clearance is not adjustable. However, to obtain the specified valve clearance, it is important that all valve components be in a serviceable condition and installed and tightened properly.

To determine whether a shorter or a longer push rod is necessary, make the following check:

1. Install an auxiliary starter switch between the battery and "S" terminal of the starter solenoid (11390) . Crank the engine with the ignition switch (11572) OFF until the No. 1 piston (6108) is on TDC on the compression stroke.

   NOTE: Tappet Bleed Down Wrench T71P-6513-B will not fit on the Mustang Cobra roller rocker arms (6564) .

2. With the crankshaft (6303) in the positions designated in Steps 4, 5 and 6, position Tappet Bleed Down Wrench T71P-6513-B on the rocker arm . Slowly apply pressure to bleed down the valve tappet until the plunger is completely bottomed. Hold the valve tappet in this position and check the available clearance between the rocker arm and the valve stem tip with a feeler gauge.
   
   
   
   

3. With the No. 1 piston on TDC at the end of the compression stroke, POSITION 1 and check the following valves:

   No. 1 intake No. 1 exhaust

   No. 4 intake No. 3 exhaust

   No. 8 intake No. 7 exhaust

4. After these valves have been checked, rotate the crankshaft to POSITION 2 and check the following valves:

   No. 3 intake No. 2 exhaust

   No. 7 intake No. 6 exhaust

5. After these valves have been checked, rotate the crankshaft to POSITION 3 and check the following valves:

   No. 2 intake No. 4 exhaust

   No. 5 intake No. 5 exhaust

   No. 6 intake No. 8 exhaust

   NOTE: If the clearance is less than specification, install a shorter push rod . If the clearance is greater than specification, install a longer push rod .