CYLINDER HEAD-E.4 E11 COMBUSTION CHAMBER INSERTS These can be gently tapped out of their locations by means of a short length of curved bar through the atomiser bore. When refitting they must be located by means of expansion washers in the recesses provided, as shown in Figs. E.8 and E.g. E13 Cleaning Remove any carbon from the cylinder head. If the water jacket within the cylinder head shows signs of excessive scale, then a proprietary brand of descaling solution may be used, if possible the cylinder head should be tested for water leakage after such treatment at the pressure given on Page B.7.
VALVE GUIDES The worn guides should be removed either by means of a press and a suitable "dolly" or the valve guide removal tool shown in Fig. E.10. Before fitting the new guides remove any burrs from the cylinder head parent bores, then smear the bores with clean oil and either press in the new guides or pull them in by means of the tool shown in Fig. E.11, until the guide protrusion above the head top face is that quoted on Page B.7. NOTE: Special care should be exercised during this operation as the guides, being made of cast iron, are therefore comparatively brittle. VALVE SPRINGS It is advisable to fit new valve springs whenever the engine undergoes a major overhaul.
Where a top over- haul only is being carried out the springs should be examined, paying particular attention to squareness of ends and pressures developed at specific lengths, the details of which can be found on Page B.8. E12 E14