VALVE 8J6308 - Caterpillar

--------------- END SUPPLEMENT ---------------Sometimes, after grinding compacted graphite iron cylinder heads, the surface appears burned and does not meet surface texture requirements. This problem is usually caused by: 1. Using a grinding wheel that is too hard and its structure is not open enough (the abrasive particles are too close together).2. Not using a suitable coolant.
These two factors along with the characteristics of compacted graphite iron will cause the grinding wheel to load up (metal fills the spaces between the abrasive particles). This prevents the abrasive particles from removing metal from the casting. If the wheel is too hard, it does not allow the wheel to break down. The breaking down of the wheel produces a self-cleaning effect.
A grinding wheel having the following specifications should be used to grind compacted graphite iron cylinder heads.
An MS2033 coolant should be used to flood the cylinder head and grinding wheel while grinding.
Use the feed/speed rates in the chart to grind compacted graphite iron cylinder heads.
Compacted graphite iron cylinder heads are identified by a part number on the intake port side of the casting. See the chart for model and part number.
Compacted graphite iron cylinder heads from the factory may have a streaked or discolored appearance. This appearance is the result of the machining process used at the factory.Do not surface grind a used compacted graphite iron cylinder head only because it appears streaked or discolored. Before grinding, check for conformance to specifications. See "Guidelines For Reusable Parts", Form Number SEBF8055.