Article 957 - Valve Stem Tip Wear

TSB #52 - December 2, 1966
(1965-66 240 C.I.D. Engines)

If customers complain of excessive engine noise on 240 C.I.D. engines, the problem may be caused by valve stem tip wear as a result of extended idle periods or slow speed operation. To correct this condition, it is recommended that a positive rotator be installed on the exhaust valve, and that intake valves be replaced with the new improved intake valves. All 240 C.I.D. police/taxi engines built after June 1, 1966 have the improved parts.

Special precaution should be taken to assure proper seal installation in the exhaust valve stem seal groove. It is important not to damage the exhaust valve stem seal when releasing the depressed valve spring with the compressing tool.

Be certain to install positive rotators on the exhaust valves ONLY as the new intake valve foot has a harder surface.

Part NumberDescriptionClass
C5TZ-6507-AValve - intake - standardA
C5TZ-6507-BValve - intake - .003 O.S.C
C5TZ-6507-CValve - intake - .015 O.S.C
C5TZ-6507-DValve - intake - .030 O.S.C
C5TZ-6505-JValve - exhaust — standardB
C5TZ-6505-KValve - exhaust - .003 O.S.C
C5TZ-6505-LValve - exhaust - .015 O.S.C
C5TZ-6505-MValve - exhaust - .030 O.S.C
*C5TZ-6514-ARetainer - valve spring
(positive rotating)
*C5TZ-6571-AOil seal — valveB
*C5TZ-6513-ASpring - valveB
*Use on exhaust valve

Oper: Use Applicable Suggested Time Schedule Operation