Page 33 - Demo

Page 33.Alvis Three Litre Shop Manual - T.A. 21 and T.C. 21Valve spring compressor in use.No. 2 when No. 5 is fully open; and set No. 4 when No. 3 is fully open; the firing order being 1%u20145%u20143%u20146%u20142%u20144.DDe-cacarbboniisati ationThe need for de-carbonising the engine and grinding in the valves is usually indicated by a falling off of performance. The period between de-carbonisations can vary considerably with the condition of the engine and the conditions under which it is operated, but it is normally necessary to carry out this operation about every 10,000 miles (16,000 km.).De-carbonising the ALVIS THREE LITRE engine is a straight-forward operation and should be carried out as follows:%u2014Remove the bonnet top and sides; drain the water from the radiator and cylinder block; disconnect the radiator top hose; remove the air cleaner, petrol pipe, throttle control rod, distributor cover, and sparking plugs, and release the car heater pipe clip from the cylinder head rear cover stud. Disconnect the cold starting cable, distributor diaphragm connection to carburettor, carburettor drain pipe, car heater water connection, and remove the thermometer bulb from the cylinder head. Disconnect the exhaust pipes at the manifold flange, and remove the inlet and exhaust manifolds and carburettor. Remove the valve gear cover and push rods.Puush RRod RRemmovavalTo remove a push rod proceed as follows:%u2014 If necessary rotate the engine until the valve is closed, then, using a large screwdriver or steel bar as a lever, compress the valve spring by placing the end of the lever under the rocker shaft and pressing down on the valve spring cap as near to the valve