• | J 7872 Magnetic Base Dial Indicator Set |
• | J 8520 Camshaft Lobe Lift Indicator |
Caution: Wear safety glasses in order to avoid eye damage.
If the camshaft retainer plate sealing gasket is not cut or damaged, it may be used again.
• | Excessive wear or scoring. The presence of the copper color bearing material should be considered normal and not a guideline for bearing replacement. Measure the bearing inside diameter (ID) as required for an over-sized condition. Refer to Engine Mechanical Specifications. |
• | Proper fit in the engine block. Camshaft bearings have an interference fit to the engine block and should not be loose in the engine block bearing bores. |
• | Oil lubrication hole plugged by debris. |
• | Bearings with excessive wear or scoring must be replaced. |
• | A camshaft with bearing journals that measure more than 0.025 mm (0.001 in) out-of-round, must be replaced. |
• | A camshaft with bearing journal diameters that measure less that 54.99 mm (2.164 in), must be replaced. |
• | An LS1 camshaft with an intake lobe that measures 46.31 mm (1.823 in) or less, must be replaced. |
• | An LS1 camshaft with an exhaust lobe that measures 46.31 mm (1.823 in) or less, must be replaced. |
• | An LS6 camshaft with an intake lobe that measures 46.24 mm (1.82 in) or less, must be replaced. |
• | An LS6 camshaft with an exhaust lobe that measures 46.19 mm (1.818 in) or less, must be replaced. |
12.1. | Mount the camshaft in wooden V-blocks or between centers on a fixture. |
12.2. | Check the runout of the intermediate camshaft bearing journals using the J 7872 . |
12.3. | If camshaft runout exceeds 0.05 mm (0.002 in), the camshaft is bent and should be replaced. |
Important: Measuring camshaft lobe lift is a procedure used to determine if the camshaft lobes have worn. This test is to be performed prior to engine disassembly and with the camshaft and valve train components installed in the engine.
1.1. | Remove the valve rocker arms and bolts |
1.2. | Install the dial indicator mounting stud into the valve rocker arm bolt hole. |
1.3. | Assemble the components of the J 8520 and position onto the stud. |
1.4. | Position the shaft of the dial indicator onto the end of the pushrod. |
1.5. | Rotate the face of the dial indicator to zero. |
1.6. | Slowly rotate the crankshaft clockwise until the dial indicator obtains its highest and lowest readings. |
1.7. | Compare the total lift shown to specifications. |
• | The proper lobe lift for the LS1 intake lobes is 6.96 mm (0.274 in). |
• | The proper lobe lift for the LS1 exhaust lobes is 7.13 mm (0.281 in). |
• | The proper lobe lift for the LS6 intake lobes is 8.24 mm (0.324 in). |
• | The proper lobe lift for the LS6 exhaust lobes is 8.19 mm (0.322 in). |
1.8. | Remove the tool. |
If the readings are not within specifications, remove the camshaft. Inspect and/or replace components as required.