MG MGA Twin Cam Workshop Manual page 31

A
THE ENGINE
Section A.7
HEADER TANK
Removal
Remove the heater air intake pipe.
Slacken the hose clips between the thermostat housing
cover and the header tank.
Remove the two set screws, spring washers, and plain
washers securing the header tank mounting bracket at
the rear of the tank. Release the overflow pipe at the
rubber connection to the filler neck and lift out the
header tank.
Repbcement
Replacement is a reversal of the above instructions.
Section A.8
THERMOSTAT HOUSING
Removal
Remove the beater air intake pipe, thermostat cover,
and header tank as detailed in Section A.7.
Slacken the beater water pipe union nut and release
the pipe from the thermostat housing. Release the thermal
transmitter bulb olive nut and withdraw the thermal
transmitter. Release the hose clip securing the hose
between the thermostat housing and cylinder bead.
Remove the three bolts, nuts, and spring washers
securing the thermostat housing to the front engine plate.
Push the housing into a position which will enable the
clip on the by-pass hose to be slackened.
The thermostat housing can now be· removed.
Replacement
Replacement is a reversal of the above instructions.
Section A.9
EXHAUST
~FOLDS
Removal
Drain the cooling system. Remove the header tank
as detailed in Section A. 7 and
the thermostat housing
as described in Section A.8. Remove the heater water
intake
pipe
if fitted. Remove the six nuts and washers
connecting the exhaust pipes to the manifolds. Release
the exhaust pipe bracket from the gearbox mounting
plate. Remove the nuts and washers securing the exhaust
manifold to the cylinder head and withdraw the manifolds.
Re, p bcemeDt
Replacement is a reversal of the above instructions. A
new gasket should be
used .
.4.4
Section A.lO
CAMSHAFT DRIVING SPROCKETS
Discounecting
When the camshafts or cylinder bead a re removed it is
necessary to first disconnect the camshaft driving
sprockets from the driving flanges on the camshafts.
Proceed as foiiows.
Remove the three set screws, spring washers, and plain
washers securing the front end of each camshaft cover
and the three domed nuts and copper washers along the
top of the covers. Lift off the camshaft
covers.
Mark the
camshaft sprockets and the driving flanges so that the
sprockets may
be
replaced in their origiaal positions on
assembly.
Slacken the timing chain tensioner adjusting screw
right off.
Remove the locking wire from the two set screws
securing each camshaft driving sprocket to the camshaft
flange and slacken the screws. Slacken the two nuts
securing the camshaft sprocket support plate to the
timing chain cover. Puii the camshaft sprocket and sup-
port spindle away from the camshaft flange and engage
the thread on the spindle with the support plate (see Fig.
A.2). Remove the driving sprocket set screws completely.
Fig. A.2
The
sprocket support spindle thread engaged in the
support plate
Recoanectiog
When reassembling the driving sprockets to the
camshaft, line up the marks (made on removal) on the
flanges before fitting the sprocket securing screws.
Rewire the screws after final tightening.