I have a Lehman 120 and I would like to check the valve lash. I have the manual and I have searched the topic on TF. I took the rocker cover off the engine but I couldn't figure out which was the intake valve and which was the exhaust valve. I assume that the arrangement is the same for all 6 cylinders.
Suggestions?
I just went through this, that is, even though having the manual I wasn't able to be certain of the procedure. I am certain now. I put together a paper on how to do it. Once you do it you will wonder how it was so daunting beforehand. Once caution: per Brian Smith, the heads must be re-retorqued before adjusting the valves on a FL120. On a FL135, just the opposite, do not touch the heads. The reason is the type of head bolts that were used. See below. Note that the rocker assembly must be loosened to get at one of the head bolts. One other piece of advice: do not use a cheap torque wrench. A wrench with a flexing needle is what I am talking about.
Valve Setting Procedure for Ford Lehman 120/135
Intake Valve Lash (120) - .012
Exhaust Valve Lash (120) - .015
Intake Valve Lash (135) - .015
Exhaust Valve Lash (135) - .015
Valve Sequence from Front of Motor:
Valve 1 – Exhaust
Valve 2 – Intake
Valve 3 – Exhaust
Valve 4 – Intake
Valve 5 – Intake
Valve 6 – Exhaust
Valve 7 – Exhaust
Valve 8 – Intake
Valve 9 – Intake
Valve 10 – Exhaust
Valve 11 – Intake
Valve 12 – Exhaust
To Set Valves:
Rock Cylinder 6, Set Cylinder 1
Rock Cylinder 2, Set Cylinder 5
Rock Cylinder 4, Set Cylinder 3
Rock Cylinder 1, Set Cylinder 6
Rock Cylinder 5, Set Cylinder 2
Rock Cylinder 3, Set Cylinder 4
Rocking Procedure:
Using a breaker bar and a 15/16 socket installed on the center bolt of the flywheel pulley, rotate the engine clockwise until the No.6 cylinder exhaust valve fully opens and the intake valve begins to close. The springs of both are at their highest at this point. Rock in both directions until both are not moving up or down. Then set the intake and exhaust valve lash on Cylinder No. 1.
Then rock 2, 4, 1, 5, and 3 in order. This will happen as the engine is continued to be rotated clockwise.
Note 1: The cylinder head on a Lehman 120 must be re-torqued (110 ft.-pounds) before setting the valve lash. On a Lehman 135 the head must NOT be re-torqued.
Note 2: The rocker arm assembly must be loosened and the last rocker retainer slid off the tube in order to access head bolt No. 22. The fuel return line is in the way.