Inspect

Cylinder Head - Decarbonise

Service Repair No - 12.29.19

Inspect
1. Check cylinder head face for warping, across center and from corner to corner
2. Check condition of valve springs and measure free length of springs.
3. Decarbonize combustion chambers.
4. Check existing valve stem diameters.
5. Check valve guide clearance using new valves.
6. Renew valves and guides as necessary.
7. To replace valve guides support cylinder head face down on wooden blocks.





8. Position LRT-12-519-3 in tappet bore and drift out valve guide using LRT-12-519-1.





9. Identify type of valve guide fitted: A-Standard production C-Production oversize

NOTE: Two sizes of replacement valve guides are available, sizes B and D, replace guide A with B and guide C with D.





10. Locate valve guide in valve guide bore with identification groove(s) towards valve seat and position depth gauge LRT-12-519-2 onto valve guide.
11. Position nylon guide LRT-12-519-3 in cylinder head, press guide into bore using driver LRT12-519-1 until depth gauge contacts cylinder head.





12. Check that fitted height of valve guide, `A', is 6.00 mm.
13. Check condition of valve seats and existing valves that are to be re-used.
14. Cut new valve seat using pilot MS120-6 and the following seat cutters: 150 MS76-120-To cut the first angle. 45° To make final cut and remove any burrs. 60° To narrow valve seat and obtain correct valve seat width.
15. Cut valve face and seat angles to the following: Valve face angle= 45° Valve seat width:-Inlet = 1.2 mm, Exhaust = 1.6 mm. Valve seat angle:-45°-Inlet and Exhaust.
16. Reface valves.
17. Lap each valve in using a fine grinding paste.
18. Apply Prussian Blue to valve seat, insert valve and press it into position several times without rotating, Remove and check valve for even and central seating: seating position shown by Prussian Blue should be in the center of valve face: a: High towards stem, increase 60° cut and restore seat width. b: Low towards edge, increase 45° cut and restore seat width. Lap and recheck valve seating.
19. Check valve stem fitted height.
20. Clean combustion spaces and manifold ports.
21. Using an airline, blow out combustion spaces.
22. Clean valves.
23. Clean spring caps and collets.
24. Clean valve springs and lubricate valves.