MG Midget J1 1933 Instruction Manual page 33

Fill
the radiator with water, start up the engine and let it run quietly
until it is thoroughly warm. Then, switching off again, remove the valve
cover and go over each of the cylinder head nuts in turn, giving each a final
tightening up. It will be found that now the engine is warm an extra half
turn o r so can be giv,en to each nut. D o not attempt to speed up th'e engine
until this final tightening has been effected. Start up the engine and ascertain
that oil is exuding from the small oil passage drilled in each roclter-arm, and
lubricating the cam surfaces. If oil is coming freely from these oil passages,
the valve cover can be replaced, together with the bonnset, and the car is
ready for the road.
About
100
miles after the cylinder head replaccement, it is advisable to
go over the cylinder head nuts once again (when the engine is warm) to
ensure that th,ey are absolut,ely tight, and also check the valve rocker clear-
ances.
Rocker Clearance. T h e good tune of ,engines is frequently spoilt through
the owner weking silenc'e by cutting down the rocker clearance. I n order to
maintain good tune over long periods it is advisable to set th,e rocker clear-
ance o n e o r even two thousandths more than the amount indicated earlier.
This may increase the valve gear noise b ~ ~ t will undoubtedly lead to improved
maintenance of tune o-rler lengthy periods.
It is particularly important to check the clearances
100
miles o r so after
grinding, as the valves have a tendency to
"
bed down," and clearances
should be check'ed subsequently every
2,000
miles.
Engine Bearings. T h e mileagse which may be covered before th,e main
and big-end bearings require attention will depend ,entirely upon the care
given to correct lubrication and the way in which the car is driven, particularly
when new. Owners are not recomm'ended to undertake this overhaul
thems'elves, particularly when th'e standardised charges allow such jobs to be
don'e cheaply and efficiently by
M.G.
agents all over the country.
Clutch. Th'e clutch is provided with two friction surfaces. T h e driving
surfaces comprise two rings of bondted asbestos fabric, o n e attached to the
flywheel cover-plat'e and the other attached to the pressure plat'e. Six driving
pins pass through the flywheel, pressune plate and flywhe'el cover-plate, all of
which consequently revolve together.
T h e driven surfaces comprise both sides of a single steel disc splined to
the driven shaft. Driving pressure for th,e clutch is derived from six helical
springs housed betwmeen the pressure plate and the flywheel.
T h e clutch must be run dry, and persistent slipping of the clutch is usually
an indication that oil has found its way into the clutch compartment, in which
case it will be necessary to remove the drain plug in the bottom of the clutch
housing and drain away any oil which may be present.
Oil
which may then
be still adhering to the surface of the clutch plates will soon be burnt away
after a little use.
If the clutch is allowed to slip continuously the centre driven plate very
quickly becomes excessively hot, and the heat and friction will v,ery soon
destroy the surfaces of th,e fabric facings.
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TWENTY-SIX J / A