Page 94 - Vauxhall 20-60 H.P. (R Type) Chassis Shop Manual

VAUXHALL 20-60 SHOP MANUAL

TO REPLACE

SECTION Reverse operations given for removal ( Section 427 ). As the camshaft
429 is being replaced, special care must be taken when meshing the camshaft
gear with the driving gear of the pump, to avoid damaging the teeth. Finally
replace and re-time distributor ( Section 434 ).

CAMSHAFT BEARINGS — TO REMOVE

SECTION – Remove timing chain ( Section 421 ) .
430 – Remove camshaft ( Section 427 ).

– Remove camshaft chain sprocket and front end bearing.

The centre bearing is located by a set screw in the nearside centre of the
crankcase. After removing the set screw the bearing can be withdrawn. To
remove the rear camshaft bearing, remove engine ( Section 400 ), clutch,
flywheel, and flywheel housing ( Section 401 ). Drive out the expansion
plug fitted in the end of the rear bearing housing. The bearing can then be
withdrawn.

TO REPLACE

SECTION – Press camshaft bearings into position, taking care to line up oil holes
431 correctly. Press expansion plug into rear bearing housing. A new expansion
plug will be necessary, as the original one is invariably damaged when
removed.

For further reassembly, reverse operation given for removal, ( Section 430 ).

VALVE TIMING — ( Before R3061 )

SECTION The valve clearance of .020” is taken up in 120° and 128° of crankshaft
432 rotation for inlet and exhaust valves respectively. The inlet valve commences

to rise in mask 41” before T.D.C. and clears the mask 5” past T.D.C., sinking
into the mask at 35” past B.D.C., closing completely at 81° past B.D.C. The
1
exhaust valve opens 67 / ° before B.D.C. and closes 31 / ° past T.D.C. With
1
2 2
the engine in position, the valve timing may be checked off the flywheel.
The flywheel is marked by a line and T.D.C.

– Remove the flywheel inspection cover situated on the nearside of
the flywheel housing and turn the engine over by hand until the line
on the flywheel marked T.D.C. is opposite the mark on the side of
the inspection hole. No. 1 piston is then at T.D.C. Now turning the
crankshaft through an arc equal in length to the distance between
the centres of two adjacent teeth on the periphery of the flywheel is
equal to 3° of crankshaft rotation. It can therefore be assumed, for
the purpose of checking the valve timing on No. 1 cylinder that the
inlet valve opens 13 teeth before T.D.C. and exhaust valve closes 10
teeth after T.D.C. as marked on the flywheel.

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