Camshaft Identification; Inspection - Triumph Thunderbird Service Manual

Cylinder Head
Camshaft identification
The exhaust camshaft can be identified by the
decompressor fitted to each end. The inlet camshaft has
no decompressors fitted.
4. Inspect the decompressors for damaged or missing
flyweights or worn or broken springs. Carefully
inspect the cam on each decompressor for damage
or wear.
5. Check camshaft journal to camshaft ladder clearance
using Plastigage <Triumph part number
38801S0-T0301) as follows:
cfue
cftq
a) Position a camshaft to the cylinder head in its
correct location, (inlet camshaft to inlet valves,
exhaust camshaft to exhaust valves). Ensure
that the timing marks on the camshaft sprocket
are positioned as for removal.
b) Wipe the exposed areas of one of the camshaft
journals and the corresponding position on the
camshaft ladder.
c)
Apply a thin smear of grease to the wiped
camshaft journal and a small quantity of silicone
release agent to the corresponding position on
the camshaft ladder.
d) Size a piece of Plastigage to fit across the wiped
camshaft journal.
e) Fit the Plastigage to the camshaft journal using
the grease to hold it in place.
f)
Position the camshaft ladder to the cylinder
head, aligning bearing areas with camshaft
journals. At this stage, it is not necessary to fit
the camshaft drive chain top pad.
g) Finger-tighten the camshaft ladder bolts until
the under-head areas are in contact with the
camshaft ladder.
h) In the sequence shown below evenly and
progressively tighten the camshaft ladder bolts,
approximately half a turn each, until the
camshaft ladder is in full contact with the
During the following procedure, the engine must not be
rotated. Damage to valves, pistons and the cylinder head
can result from rotating the engine.
Camshaft Identification <Inlet - viewed from
the rear of the engine)
1. Inlet camshaft
2. Thrust face
2
\
Camshaft Identification (Exhaust - viewed
from the rear of the engine)
1. Exhaust camshaft
2. Thrust face
3. Left hand decompressor
4. Right hand decompressor
Inspection
1. Inspect the camshaft sprockets for damage and worn
or broken teeth.
2. Inspect the bearing surfaces in the cylinder head and
camshaft ladder. If wear or damage is found, the
cylinder head must be replaced.
3. Inspect the camshaft drive chain (see page 3-1J).
3.16
SelVice Manual - Thunderbird