Triumph TR2 Service Instructions Manual page 56

ENGINE
( 0 )
Fit the distributor cover, connect the
plug leads to the correct plugs (Fig. 26).
The plugs having had their gaps set to
.032". Fit the H.T. and L.T. leads to
the ignition coil.
14. TO DECARBONISE
We recommend the removal of the cylinder
head for decarbonising after the first 5,000
miles. Attention after this running period
has the advantage of allowing the initial
casting stresses to resolve themselves and
permits the consequent valve seat dis-
tortion to be counteracted by valve grinding.
Failure to carry out this initial valve
grinding is a frequent cause of excessive
petrol consumption of new cars. Sub-
sequent attention will not normally be
required until further considerable amount
of running has been done-normally after
about 15,000 miles.
The above mentioned figures only take into
consideration a car which is used under
normal conditions. If the car is being used
for competition and high speed work valve
grinding is done as and when necessary.
The procedure recommended for de-
carbonising is as follows
:-
(a)
Disconnect the battery lead and plug
leads from plugs.
(b) Drain the cooling system.
(c) Disconnect the fuel pipe clip, the top
water and by-pass hoses and remove
the thermo gauge bulb from the
thermostat housing, then remove the
latter from the cylinder head by with-
drawing the two bolts.
(d) ~ e m o v e the two rocker cover securing
nuts and lift off the rocker cover.
(e)
Remove the rocker shaft assembly by
loosening off the four pedestal nuts
progressively, allowing the assembly to
rise as a unit.
( f ) Remove the heater hose from the water
shut-off cock at the rear of the cylinder
head. (Where heater is fitted.)
(g) Disconnect the throttle and choke
controls, the suction pipe and fuel feed
pipe from the carburettors. Whilst
there is no need to remove the car-
burettors this can be effected at the
carburettor and manifold joints. (See
"Fuel" Section
P.)
(h)
Remove the ten cylinder head nuts and
lift tbe head 5on: the block. Do not
Fig. 26
Plug Lead
Attachment Sequence.
attempt to break the seal of the cylin-
der head by turning the engine as this
will disturb the cylinder sleeves.
(i) Immediately the combustion head has
been removed, place cylinder liner
retainers in position (Fig. 22) and
check the projection of the cylinder
sleeves above the face of the cylinder
block (Fig. 5). The flange of the
cylinder sleeves should stand proud by
.003" minimum to .0055" maximum. If
the cylinder sleeves have sunk below
.003" new figure of eight joints will
need to be fitted. (See page 19.)
Inspect also for cylinder sleeve move-
ment and if any is suspected the
cylinder sleeves and pistons will have
to be removed and new figure of eight
joints fined.
Remove the push rods.
13.
VALVE
GRINDING
Lay the cylinder head on a bench so that
the valve heads are supported, this will en-
sure that when pressure is exerted on the
valve spring cap this spring will compress
and the cotters easily removed.
The valves are numbered from the front of
the engine and their positions perpetuated.
The carbon should be cleaned off with a
blunt instrument and finally cleaned with a
petrol moistened rag.
Grind the valves into their appropriate
seating, where valve faces are badly pitted
they should either be renewed or replaced.
No attempt should be made to grind a
badly pitted valve into its seating or this will
be unduly reduced.
When the xcessity af r p n ~ t h g
B
d v e sear