Usage:
3606 (8RB),
3608 (6MC),
3612 (9RC),
3616 (1PD) Industrial;
3616 (1FN) Marine Engines
Description of Change: Changes have been made to the salvage procedure for cylinder head assemblies in the above engines. The following changes affect the procedure for grinding the contact faces on the valve seat inserts:
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- * The 134-5506 [16.06 mm (.632 in) diameter], 134-5507 [16.09 mm (.633 in) diameter], and 134-5508 [ 16.12 mm (.635 in) diameter] Pilots replace the former 4C-4708 Pilot.
NOTE: The size ranges of the above pilots are to accommodate various wear stages of the inside diameter of the valve guide. Different wear rates are encountered when salvaging cylinder heads. It is recommended that all three sizes of pilots are available. The new pilots provide a more stable method for centering the grinding wheel.
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- * The angle of the valve seat insert contact face has changed. The valve seat insert contact face must be machined with a grinder to 30.5 degrees to 31 degrees. Lapping the valve seat to full face contact is no longer needed.
NOTE: Two gauges are available to measure the valve seat angle.
1. In order to measure the insert seat angle to determine if it is more than 30.5 degrees, apply a light coat of Prussian Blue© on the 147-1642 Angle Gauge (30.5 degree). The 147-1642 Angle Gauge is a component of the 147-2285 Valve Gauge.
2. Install the gauge in the valve guide bore until the gauge is approximately 25.4 mm (1.00 in) from the valve seat face. Allow the gauge to drop onto the valve seat face.
3. Use one finger to slightly push down on the top of the gauge and rotate the gauge 15 to 30 degrees. Remove the gauge and check the pattern on the valve seat face.
NOTE: If the seat angle is machined correctly, the line contact will be at the top edge of the valve seat face, with contact for a full 360 degrees. If the line contact is not at the top edge, it is necessary to adjust the angle by adjusting the dresser, dressing the wheel again, and grinding the valve seat face again.
4. In order to measure the insert seat angle to determine if it is less than 31 degrees, apply a light coat of Prussian Blue on the 147-1643 Angle Gauge (31 degree). The 147-1643 Angle Gauge is a component of the 147-2285 Valve Gauge.
NOTE: If the seat angle is machined correctly, the line contact will be at the bottom edge of the valve seat face, with contact for a full 360 degrees. If the line contact is not at the bottom edge, it is necessary to adjust the angle by adjusting the dresser, dressing the wheel again, and grinding the valve seat face again.
5. Check the line contact for a full 360 degrees on the bottom edge of the valve seat face with the 147-1643 Angle Gauge. Check the bottom edge of the valve seat face with the 147-1642 Angle Gauge in order to make sure the valve seat angle is more than 30.5 degrees. If the 147-1642 Angle Gauge does not indicate contact for a full 360 degrees on the top of the valve seat face, the valve seat face must be machined again.