Engine - complete reassembly (903 cc engine)

Engine / Engine - complete reassembly (903 cc engine)

Crankshaft and main bearings 1 With the cylinder block inverted on the bench, wipe out the crankcase shell bearing seats and fit the half shells so that their tabs engage in the notches (photo).

20.1 Fitting a main bearing shell

2 Stick the semi-circular thrust washers either side of the centre bearing in the crankcase using thick grease. Make sure that the oil grooves are visible when the washers are fitted (photo).

20.2 Crankshaft thrust washer

3 If the original bearing shells are being refitted, make sure that they are returned to their original positions.

4 Liberally oil the bearing shells and lower the crankshaft into position. Make sure that it is the correct way round (photos).

20.4A Oiling main bearing shells

20.4B Lowering crankshaft into position

5 Wipe out the main bearing caps and fit the bearing shells into them.

6 Oil the crankshaft journals and fit the main bearing caps, the correct way round and in proper sequence (photo).

20.6 Fitting a main bearing cap

7 Replace the main bearing cap bolts and screw them up finger-tight.

8 Test the crankshaft for freedom of rotation.

Should it be very stiff to turn, or possess high spots, a most careful inspection must be made, preferably by a skilled mechanic with a micrometer to trace the cause of the trouble.

It is very seldom that any trouble of this nature will be experienced when fitting the crankshaft.

9 Tighten the main bearing bolts to the specified torque wrench settings (photo).

20.9 Tightening main bearing cap bolts

10 Using a dial gauge or feeler blades inserted between a thrust washer and the crankshaft, check the crankshaft endfloat. If it exceeds the specified limit, the thrust washers can be changed for thicker ones (photo).

20.10 Checking crankshaft end float

11 Bolt on the crankshaft rear oil seal carrier using a new gasket. The carrier should have been fitted with a new oil seal and the seal lips greased (photos).

20.11A Crankshaft rear oil seal carrier and gasket

20.11B Crankshaft oil seal and carrier fitted

12 Fit the engine rear plate (photo).

20.12 Engine rear plate

Flywheel
13 Offer the flywheel to the crankshaft. With pistons No. 1 and 4 at TDC, the dimple on the flywheel must be uppermost.

14 Screw in and tighten the bolts to the specified torque. The crankshaft may be held against rotation by either jamming the starter ring gear or placing a block of wood between one of the crankshaft webs and the inside of the crankcase (photo).

20.14 Tightening flywheel bolts

Camshaft
15 Oil the cam followers and return them to their original positions (photo).

20.15 Cam followers

16 Oil the camshaft bearings and insert the camshaft, taking great care not to damage the bearings with the cam lobes. Fit the front bearing, chamfer inwards (photos).

20.16A Fitting camshaft

20.16B Camshaft front bearing

17 Screw in the camshaft front bearing lockscrew (photo).

20.17 Camshaft front bearing lockscrew

Oil pump
18 Refit the oil pump as described in Section 10.

Timing chain and sprockets 19 Fit the timing chain and sprockets as described in Section 6. Fit the Woodruff key to the crankshaft nose.

20 Using a new gasket, fit the timing chain cover, but leave the bolts finger tight (photo).

20.20 Timing cover

21 Apply grease to the lips of the timing cover oil seal and then push the crankshaft pulley into position.

22 Move the timing cover if necessary so that the pulley hub is centralised in the oil seal and then tighten the cover bolts.

23 Screw on the crankshaft pulley nut and tighten to the specified torque (photo).

20.23 Tightening crankshaft pulley nut

Piston/connecting rods 24 Fit these as described in Section 9.

Sump pan
25 Fit the sump pan as described in Section 8.

Cylinder head
26 Stand the engine upright and fit the cylinder head as described in Section 7.

27 Insert the pushrods in their original fitted order.

28 With the rocker arm adjuster screws fully unscrewed, locate the rocker gear and screw on the fixing nuts.

29 Adjust the valve clearances as described in Section 5.

30 Locate a new gasket in position and fit the rocker cover (photo).

20.30 Rocker cover nut and thrust plate

31 Screw on a new oil filter (Section 2).