4.3 - | Cylinder head assemblies: camshafts

1 | Screw

2 | Vertical cylinder head inner timing belt cover

3 | Seal

4 | Screw

5 | Washer

6 | Horizontal cylinder head inner timing belt cover

7 | Screw

8 | Valve cover

9 | O-ring

10 | Vertical cylinder head

11 | Horizontal cylinder head

12 | Stud bolt

13 | Stud bolt

14 | Nut

15 | Key

16 | Camshaft-vertical cylinder head

17 | Intake manifold

18 | Screw

19 | O-ring

20 | Camshaft end cap

21 | Screw

22 | Horizontal cylinder head camshaft

23 | Copper gasket

24 | Screw

Parts catalogue

CYLINDER HEAD: TIMING SYSTEM
Vertical cylinder head
HORIZONTAL CYLINDER HEAD
INTAKE MANIFOLDS

Important
Bold reference numbers in this section identify parts not shown in the figures alongside the text, but which can be found in the exploded view diagram.
Removal of the intake manifolds

Operation | Section reference
Remove the throttle body | L 6, Removal of the throttle body

Notes
The procedure can also be carried out with the engine installed in the frame. For clarity, the photos show the engine removed from the frame.
Unscrew and remove the nuts (14) securing the intake manifolds of the vertical and horizontal cylinder heads from the studs (13).
Remove the manifolds (17).
If necessary, remove the studs (12) and (13) from the cylinder heads.
Refitting the intake manifolds
Apply the recommended threadlocker to the studs (12) and (13), install them in the cylinder heads and tighten them to the specified torque (Sect. C 3, Engine torque settings).
Locate the intake manifolds (17) and secure with the nuts (14).
Tighten the nuts (14) to the specified torque (Sect. C 3, Engine torque settings).

Operation | Section reference
Refit the throttle body | L 6, Refitting the throttle body

Removal of the inner timing belt covers

Operation | Section reference
Remove the camshaft timing pulleys | N 4.2, Removal of the timing system assembly

Notes
For clarity, the figures show the cylinder head removed from engine.
Remove the retaining screws (18) and (1) and remove the inner timing belt cover (2) from the vertical cylinder head (10).
Repeat the operation for the horizontal cylinder head (11).
Notes
When removing the covers, take care not lose the Woodruff keys (15) located on camshafts (16) and (22).
Unscrew the screws (21) of the end cap (20) of the camshaft (16).
Remove the camshaft end cap (20) from the cylinder head and recover the O-ring (19).
Removal of the valve covers
Undo the retaining screws (7) of valve covers (8) and remove the covers with relative O-rings (9).
Refitting the valve covers
Always fit new O-rings (9) when refitting the valve covers.
Fix the valve covers (8) with the relative O-ring (9) to the cylinder head.
Tighten the screws (7) to the specified torque (Sect. C 3, Engine torque settings).
Removal of the camshafts

Operation | Section reference
Remove the timing belt covers and the timing belts | N 4.2, Removal of the timing belt covers
Remove the camshaft timing pulleys | N 4.2, Removal of the timing system assembly

Notes
This operation can be carried out with the rocker arms installed in the cylinder head. For clarity, the photos show the cylinder head with the opening rocker arms removed.
Remove the camshaft end caps as described above.
Remove the key (15) from the camshaft.
Notes
To prevent possible damage to components, rotate the camshaft (16) carefully as you go so that the cam lobes do not foul the rockers.
Notes
If the rocker arms are installed in the cylinder head, remove the spring (A) of the opening rocker arm (B) to facilitate operations.
Withdraw the camshaft (16) from its housing.
Remove the oil seal (3) from the cylinder head.
Inspecting the camshafts
Check the cam contact surfaces for scratches, grooves, steps and waving. Worn cams are frequently the cause of poor timing, which leads to loss of engine power.
Install the camshaft between two centres and check for distortion using a dial gauge:
- service limit:
0.1 mm.
Notes
The effective distortion will be half the total reading obtained on the dial gauge.
Each camshaft is stamped with an identification letter:
O: horizontal;
V: vertical.
Checking the oil seals
Fit new oil seals at each engine overhaul.
Insert the new oil seals squarely in their bores. Use suitable drifts.
Lubricate the lip of oil seals after assembly. This operation must be performed very carefully.
Refitting the camshafts
If removed, install the oil seal (3) in the bore on the right-hand side of the cylinder head using a suitable drift.
Important
If the rockers arms are already installed in the cylinder head (Sect. N 4.4, Refitting the rocker arms, shims and valves), insert the camshaft (16) carefully rotating it as you go, so that the camshaft lobes do not foul the rocker arms.
Before fitting the camshaft, check the punch mark: “V” means vertical, “O” means horizontal.
Apply graphite oil to the seats of the camshaft so that it is lubricated also during the initial revs of the engine.
Insert the camshaft (16) from the left-hand side of the cylinder head.
If previously removed, relocate the spring (A) of the opening rocker arm (B).
Check the condition of the Woodruff key (15) and its groove, and install it.

Operation | Section reference
Refit the inner timing belt covers | N 4.3, Refitting the camshaft end caps
Refit the camshaft timing pulleys to the cylinder heads | N 4.2, Refitting the timing system assembly
Refit the timing belts and timing covers | N 4.2, Refitting the timing belt covers

Refitting the camshaft end caps
Lubricate the new O-rings (19) with the recommended grease and fit on the end cap (20).
Fit the end cap (20) on the left-hand side of the cylinder head.
Secure the end cap (20) with the screws (21).
Tighten the screws (21) to the specified torque (Sect. C 3, Engine torque settings).
Notes
Take care not to dislodge the key (15) located on camshaft (16).
Locate the inner timing belt cover (2) of the vertical cylinder head (10) on the left-hand side of the cylinder head and insert the retaining screws (1) and (18).
Tighten the screws (18) and (1) to the specified torque (Sect. C 3, Engine torque settings).
Repeat the above operations for the other cylinder head (11).

Operation | Section reference
Refit the camshaft timing pulleys to the cylinder heads | N 4.2, Refitting the timing system assembly

N