Note: To minimize wear, it is essential that the rocker arms, valve lifters, valves and related components are installed in their original positions.
1. From the removed cylinder head, unscrew the rocker arm lock nuts, lift the rocker arm hinge washers. Remove the rocker arms.
2. Remove the valve lifters from the cylinder head, keeping them with the corresponding rocker arms.
3. Remove the camshaft from the cylinder head.
4. Remove the valves by compressing the valve spring with a puller and lifting the crackers. Release the compressor, remove the valve spring retainer, spring and spring seat.
5. Remove the valves.
6. Lift the valve stem seals off the valve guides. Lift the valve turn mechanisms that are fitted to the exhaust valves.
7. Clean carbon deposits from the valves and combustion chambers and passages. The piston crowns can also be cleaned at this stage, but be careful not to allow carbon deposits to get between the pistons and cylinder passages.
8. Check the condition of the valve heads and valve seats. If there is light corrosion on the valve and seat, it can be removed by lapping the valve and seat. If the pitting is deep, the valves must be reground on a valve lapping machine and the seats must be ground down with a roller. Both of these actions should be carried out by an Opel dealer.
9. Check the condition of the valve guides by inserting the valve into the guide and moving it from side to side. If the clearance exceeds the value given in the specifications, the valve guides must be replaced.
10. Lapping of valves is carried out as follows. Apply coarse paste to the valve head and, using a vacuum machine to process the valve chamfer, lap the valve into the seat with a rotating motion, lifting and turning the valve from time to time. When a matte smooth surface appears on the valve and seat, wash off the coarse paste. Repeat the action with fine paste until you get a slightly gray-matte continuous ring on the valve and valve seat. Carefully wash off all traces of paste.
11. Check the condition of the valve springs, if possible, compare their length with the new spring. Replace them if necessary.
12. Check for distortion (deformation) cylinder head surface. If the distortion is greater than the maximum value given in the Specifications, it may be possible to machine the head. Consult your Opel dealer if necessary.
13. Begin assembly by installing the valve rotation mechanism to the exhaust valve guides.
14. Place the oil seals on the guides.
15. To install the valves, lubricate the valve stem with engine oil and insert it into the valve guide.
16. Install the spring and spring retainer, then use a spring puller to compress the spring until the valve locks can be properly seated in the grooves in the valve stem. Slowly release the compressor and check that the valve locks are properly seated.
17. After installing all valves, tap them lightly to ensure proper valve lock bearing surface.
18. Lubricate the camshaft bearings and projections with clean engine oil, insert the camshaft into the cylinder head.
19. Lubricate the valve lifters and install them in the cylinder head.
20. Lubricate the rocker arms and install them on their stands.
21. Lubricate the pivot point washers, install them on the rocker arms with the rounded surface down. Screw on the rocker arm lock nut, adjust each valve lifter as described in Chapter 13.
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