Cylinder Head Description; Camshaft Cover; Removal - Triumph 2012 Tiger 800 Service Manual

Cylinder Head

Cylinder Head Description

The engine is fitted with an aluminium alloy cylinder head,
which carries the camshafts, valves and spark plugs. The
cylinder head is cast as a single entity and various
components are permanently added after machining.
The camshafts run directly in the head without separate
bearings. Valve clearances are adjusted by changing
variable thickness shims which sit between the valve
tappet bucket and the valves.
The camshafts are driven by a silent-type chain. The chain
is guided by two blades and is tensioned by a hydraulic
tensioner.
The Hydraulic tensioner is fed oil via a gal lery in the
cylinder head. The combination of oil pressure and spring
pressure pushes the plunger against the tensioner blade
which tensions the camshaft drive chain. The hydraulic
tensioner has an oil pressi,.Jre relief valve lo
plunger that is set to open between 12 - 16 bar and when
opens sprays oil through a drilling in the tensioner blade
onto the camshaft drive chain.
Oil is supplied to the head by an internal gallery. Once
supplied to the head, the oil is distributed along internal
drillings within the head casting and camshaft.
Single valve springs are used to close both the inlet and
exhaust valves. These valve springs have close wound
coils at one end to assist in the prevention of valve bounce
at high engine speed and to give a smooth valve
actuation. When assembling the cylinder head it is
important that the close wound, colour coded ends of the
springs are fitted downwards <towards the piston>. The tip
of the inlet and exhaust valves are hardened to give a
long service life.
Due to the methods used to assemble the valve seat and
valve guides to the head, these parts cannot be replaced.
In any of the fol lowing operations which necessitate the
removal or disconnection of the camshaft drive chain,
N EVER tum the engine without the camshaft drive
chain and tensioner correctly fitted and adjusted. In the
disassembled condition, the pistons will contact the
valves if the crankshaft is turned, causing severe engine
damage.
3.6
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d in the
SeiVice Manual Tiger 800 and Tiger 800XC
-

Camshaft Cover

Removal

1. Remove the rider's seat <see page 16-13).
2. Disconnect the battery, negative (black> lead first.
3 . Remove the fuel tan k <see page 10-91>.
4. Remove the airbox <see page 10-98).
5. Remove the ignition coils from the camshaft cover.
1. Ignition coils
6. Remove the throttle bodies, injectors and fuel rail
from the cylinder head (see page 10-107>.
Note:
•
lt is not necessary to disconnect the throttle
cables. I nstead, lay the assembly over the
frame during the period when the engine is
separated from the frame.
Z Progressively release the camshaft cover bolts in the
sequence shown below.