Page 31 - Demo

Page 31.Alvis Three Litre Shop Manual - T.A. 21 and T.C. 21Caarbuburettttor Aiir SSiilenccer aand CleaanerThe engine is equipped with a combined air silencer and cleaner to provide protection against dust and abrasives, which might otherwise enter the engine through the carburettor.At intervals of 5,000 miles (8,000 km.), or more frequently if found necessary, remove this unit and thoroughly wash it in petrol. When dry, dip the gauze end in clean engine oil, allowing any surplus oil to drain off before refitting. In certain countries where dust is prevalent, this operation should be carried out more frequently.Fuuel SSysttemm Mai ainttenaancceEVERY 5,000 MILES (8,000 K.M.).%u2013 Inspect and clean the fuel pump filter and sediment chamber. %u2013 Inspect and clean the carburettor petrol filter.%u2013 Clean and re-oil the carburettor air cleaner. ENGINE VALVE GEAR AND DE-CARBONISATIONTimi imingg GeaarThe camshaft is driven from the rear end of the crankshaft by a duplex roller chain lubricated by a jet of oil from the main oil gallery; the camshaft bearings are also pressure lubricated. A spring-loaded eccentric tensioner automatically tensions the timing chain and a pad of special material damps any tendency for the chain to flutter on the tension side. The chain tensioner is completely automatic and requires no adjustment; oil is fed to the sprocket bearing through the drilled anchor pin. The timing sprockets and chain are completely enclosed by the crankcase rear cover, an oil seal in the cover preventing oil from passing along the crankshaft into the clutch housing.Vaalvve Timi iminggA timing pointer can be obtained from the Works to facilitate timing the valve gear, and, if at any time it becomes necessary to carry out this operation, the following sequence of operations should be observed:%u2014Rotate the crankshaft until No. 1 and 6 pistons are at top dead centre. Place the timing pointer over the two studs in the rear face of the crankcase, adjacent to the crankcase breather, and rotate the camshaft sprocket until the tooth marked with an %u2018O is exactly opposite the pointer.The camshaft sprocket is now correctly timed relative to the crankshaft sprocket and the timing chain can be placed in position.Locate the chain tensioner, with the two springs attached, in mesh with the chain and push the tensioner anchor pin through the tensioner into the crankcase so that the slot in the end of the anchor pin engages with the horizontal peg in the crankcase. Secure the tensioner springs on the bottom anchor, and fit the tensioner pawl and spring to engage with the tensioner ratchet.The tensioner anchor pin is a push fit in the crankcase and is secured, when the rear cover is in position, by a nut and split pin at its outer end.Vaalvve GeaarBarrel tappets bear on the cams and are connected to the rockers by short, light push rods. A light coil spring is interposed between the cup of each push rod and a spring steel seating fitted in a recess machined in the top face of the cylinder