RECONDITIONING CYLINDER HEADS Chapter 9 u Page 209 Classroom Manual u Page 207 Lab Manual
CHAPTER OBJECTIVE n Correct valve guide clearance by: Knurling. Reaming to accept oversize valve stems. Installing bronze guide liners. Installing cast iron guide inserts. n Replace intregal and insert valve seats. n Grind valve seats & correct contact pattern.
CHAPTER OBJECTIVE n Recondition valve faces & tips. n Identify proper valve face-to-seat contact pattern. n Correct valve stem seal allignment. n Replace worn or damaged pressed-in rocker arm studs with oversize and threaded studs. n Resurface cylinder head sealing surface.
CHAPTER OBJECTIVE u Measure & correct valve guide height. u Measure & correct valve spring installed height. u Measure & correct valve stem height.
VALVES and VALVE SERVICE u Exhaust Seat temperature 800 degrees u Exhaust Valve neck temperature 1300 degrees u Depend on seat contact for cooling
Effect of Valve Lash on Cooling u Tight valves will not allow proper seating u Resulting in a burned valve
UNLEADED GAS u Valve seat wear u Loss of valve lash
Temperature Protection u Positive valve rotators u Rotators can cause excessive valve face wear u Multi-Groove keepers allow passive rotation u Check Multi-Groove valves for wear u Sodium filled valves Page 165
Exhaust and Intake Valves u Exhaust valves are smaller u Intake valves are larger u Valve stem tips are hardened
MEASURING the VALVE STEM u.001 MAXIMUM WEAR
STEM WEAR u Rocker arm side force on the valve stem causes valve stem and valve guide wear. u Figure 9-15 Page 217 Classroom Manual
OIL CONSUMPTION u Figure 9-16 Page 218 Classroom Manual
GUIDE PROTRUSION u Figure 9-19 Page 221 Classroom Manual
BEVELING GUIDE u Figure 9-25 Page 224 Classroom Manual
SEAT ANGLES u Figure 9-26 Page 224 Classroom Manual
VALVE SEAT GRINDING Page 227
VALVE SEAT GRINDING u Figure 9-33 Page 228
BEFORE TOPPING u Figure 9-36 Page 229
AFTER TOPPING u Figure 9-36 Page 229
FINISHED SEAT