Valve, Spring, and Valve Seal Installation
Valves, Springs and Valve Seals RemovalIdentify the valves and valve springs as they are removed so that each item can be reinstalled in its original position.
1. Using an appropriate-sized socket (A) and plastic mallet (B), lightly tap the valve retainer to loosen the valve keepers.
2. Install the spring compressor. Compress the spring and remove the valve keepers.
3. Install the valve guide seal remover.
4. Remove the valve seal.
Valve Inspection
Measure the valve in these areas.
Valve Stem-to-Guide Clearance Inspection
1. Slide the valve out of its guide about 10mm, then measure the guide-to-stem clearance with a dial indicator while rocking the stem in the direction of normal thrust (wobble method).
^ If the measurement exceeds the service limit, recheck it using a new valve.
^ If the measurement is now within the service limit, reassemble using a new valve.
^ If the measurement with a new valve still exceeds the service limit, go to step 2.
2. Subtract the O.D. of the valve stem, measured with a micrometer, from the I.D. of the valve guide, measured with an inside micrometer or ball gauge. Take the measurements in three places along the valve stem and three places inside the valve guide. The difference between the largest guide measurement and the smallest stem measurement should not exceed the service limit.
Valve Guide Replacement
Special Tools Required
^ Valve Guide Driver, 5.5 mm 07742-0010100
^ Valve Guide Reamer, 5.5 mm 07HAH-PJ7010B
1. Modify a commercially available air-impact valve guide driver (A) to the dimensions shown. In most cases, the same procedure can be done using the special tool and a conventional hammer.
2. Select the proper replacement guides, and chill them in the freezer section of a refrigerator for about an hour.
3. Use a hot plate or oven to evenly heat the cylinder head to 300°F (150°C). Monitor the temperature with a cooking thermometer. Do not get the head hotter than 300°F (150°C); excessive heat may loosen the valve seats.
4. Working from the camshaft side, use the driver and an air hammer to drive the guide about 2 mm (0.1 inch) towards the combustion chamber. This will knock off some of the carbon and make removal easier. Hold the air hammer directly in line with the valve guide to prevent damaging the driver.
5. Turn the head over and drive the guide out toward the camshaft side of the head.
6. If a valve guide won't move, drill it out with a 8 mm (5/16 inch) bit, then try again. Drill guides only in extreme cases; you could damage the cylinder head if the guide breaks.
7. Remove the new guide(s) from the freezer, one at a time, as you need them.
8. Apply a thin coat of clean engine oil to the outside of the new valve guide. Install the guide from the camshaft side of the head; use the special tool to drive the guide in to the specified installed height (A) of the guide (B). If you have all 16 guides to do, you may have to reheat the head.
9. Coat both reamer and valve guide with cutting oil.
10. Rotate the reamer clockwise the full length of the valve guide bore.
11. Continue to rotate the reamer clockwise while removing it from the bore.
12. Thoroughly wash the guide in detergent and water to remove any cutting residue.
13. Check the clearance with a valve. Verify that the valve slides in the intake and exhaust valve guides without exerting pressure.
Valve Seat Reconditioning
If the valve guides are worn, replace them before cutting the valve seats.
1. Renew the valve seats in the cylinder head using a valve seat cutter.
2. Carefully cut a 45° seat, removing only enough material to ensure a smooth and concentric seat.
3. Bevel the upper edge of the seat with a 30° cutter and the lower edge of the seat with a 60° cutter. Check the width of the seat and adjust accordingly.
4. Make one more very light pass with the 45° cutter to remove any possible burrs caused by the other cutters.
5. After resurfacing the seat, inspect for even valve seating: Apply Prussian Blue compound (A) to the valve face. Insert the valve in its original location in the head, then lift it and snap it closed against the seat several times.
6. The actual valve seating surface (B), as shown by the blue compound, should be centered on the seat.
^ If it is too high (closer to the valve stem), you must make a second cut with the 60° cutter to move it down, then one more cut with the 45° cutter to restore seat width.
^ If it is too low (closer to the valve edge), you must make a second cut with the 30° cutter to move it up, then one more cut with the 45° cutter to restore seat width.
NOTE: The final cut should always be made with the 45° cutter.
7. Insert the intake and exhaust valves in the head and measure valve stem installed height (A).
8. If valve stem installed height is over the service limit, replace the valve and recheck. If it is still over the service limit, replace the cylinder head; the valve seat in the head is too deep.
Valves, Springs and Valve Seals Installation
1. Coat the valve stems with engine oil. Install the valves in the valve guides.
2. Check that the valves move up and down smoothly.
3. Install the spring seats on the cylinder head.
4. Install the new valve seals (A) using the valve guide seal installer (B).
NOTE: Exhaust valve seal (c) has a black spring (D), and intake valve seal (E) has a white spring (F). They are not interchangeable.
5. Install the valve spring and valve retainer. Place the end of the valve spring with closely wound coils toward the cylinder head.
6. Install the valve spring compressor. Compress the spring and install the valve keepers.
7. Lightly tap the end of each valve stem two or three times with a plastic mallet (A) to ensure proper seating of the valve and valve keepers. Tap the valve stem only along its axis so you do not bend the stem.
Camshaft/Rocker Arms, Camshaft Seal, and Pulley Installation
Special Tools Required
^ Seal Guide 07NAG-PT0010A
^ Installer Cup 07NAF-PT0010A
^ Installer Shah 07NAF-PT0020A
NOTE: To prevent the rocker arm assembly from coming apart, leave the camshaft holder bolts in the holes.
1. After wiping down the camshaft and the journals in the cylinder head, lubricate both surfaces and install the camshaft.
2. Clean and install the oil control orifice (A) with a new O-ring (B).
3. Turn the camshaft until its keyway (c) is facing up. (No.1 piston TDC).
4. Loosen all the valve adjusting screws.
5. Apply liquid gasket to the head mating surfaces (the shaded areas) of the No. 1 and No. 5 camshaft holders.
6. Set the rocker arm assembly in place and loosely install the bolts. Make sure that the rocker arms are properly positioned on the valve stems.
7. Install the camshaft oil seal (A) using the special tools as shown.
8. Make sure all the rocker arms are aligned with the valves.
9. Tighten each bolt two turns at a time, in the sequence shown, to ensure that the rockers do not bind on the valves.
10. Check the back cover rubber seal for cranks and other damage.
NOTE:
^ If the rubber seal is coming off, reattach it with liquid gasket. Wipe off any excess liquid gasket.
^ When replacing the seal, clean the lower cover groove, cut the repair strip to length, and press the new piece into the groove evenly.
^ After installing the rubber seal, check the joints. Apply liquid gasket if there is any gap or opening.
11. Install the back cover (A).
12. Install the camshaft pulley (B) onto the camshaft, then tighten the retaining bolt to the torque shown.