Reaming Procedure
- Measure the valve stem-to-guide clearance using a dial indicator. Valve stem-to-guide clearance may also be obtained by using a micrometer to measure the valve stem diameter and a ball type measuring gage to measure the guide bore.
- A valve stem (1) and guide (2) with clearance in excess of 0.093 mm (0.0037 in) must be repaired or the components replaced.
- Inspect the valve stems for excessive scoring, wear, or warpage. A valve stem that has excessive scoring (3 or 4) or wear (4 or 6) must be replaced. A valve guide that is worn and has excessive stem-to-guide clearance should be reamed and valves with oversize stems installed.
- Measure the valve stem diameter. A valve stem with a diameter less than 7.95 mm (0.313 in) must be replaced. Position the tip of the dial indicator at the top of the valve guide. If the valve stem diameter is within specifications, and the stem-to-guide clearance is excessive, the valve guide must be reamed oversize and a valve with oversize stem installed.
- Ream the valve guide using the J 37378-1 . See «Special Tools and Equipment»(/cadillac/cts/i-2002-2007/remont/mechanical/#engine-mechanical-57l-ls6) .
- Clean the guide bore of all metal shavings and debris.
- Install the valve (227 and 228), with oversize stem, into the cylinder head (218).
- Inspect the valve for proper fit. Move the valve back and forth in the guide. The valve should move freely with no resistance or drag.