Hints
and tips
If you have any handy tips
please submit them to me so we may all share in our experiences with the 12/4
or the 20
The following articles have
been kindly supplied by Tom Stapledon of the UK so that we may all benefit
from his experiences
Clutch overhaul
Front
brake replacement
Pressure
plate overhaul
Adjusting
the steering box
If you
are going to attempt a gearbox overhaul I have an excellent article that I
can send you. just contact me
( I do not have permission to make
it public.Probably could, but I dont know how to contact the author)
1)
When doing a clutch job on the 12/4 rivet the linings onto the friction plate
instead of the flywheel, this makes for a much smoother clutch
2)
There is a modern throwout bearing being made in NZ priced at $nz195 plus
freight. I have one in the Open Road and it is really good .If you are interested,
email me & I will pass it on
3)
Rover 820 fan belt will go on the 12/4 motor, just be careful because there
appears to be slight differences in the diameter of the 12/4 fan hub
4)
Keep an eye on the joint between the block & crankcase on the drivers
side, any oil leaks here could indicate that the main bearing caps are not
tight. It allows the through bolts to lift enough to leak oil up the stems
5)
The flywheel on my open road has been lightened to 9 KGs, very satisfactory.
Gear changes are a much easier & no loss of power on the hills
see
photos
Timing
the motor
How
do I do it?
Well its really quite
simple, firstly you must have a priming cup on No1 cylinder
1) Open the priming
cup on No1 and turn the motor with the crank handle until compression starts
to hiss out, you now know that the piston is coming up to the top on the compression
stroke, when the crank handle is at either 12 oclock or 6 oclock ( depending
where you put the crank handle in.) stop cranking and you now know that you
are at TDC. Now measure from the 12 oclock position on the waterpump vernier
a distance of 8.75mm towards the motor (backwards), put a small mark there
and now turn the motor forwards by hand so that this mark is at 12 o'clock
What you have done
so far is time the motor off the flywheel so that you are 2 and 1/4 inches
before TDC which is where it is supposed to fire
2) The next part is
to set the mag up so that it just about to fire on No1 lead
3) Now marry the
two together using the rubber vernier block This is sufficient to get the
motor running..... now comes the final adjustment
4) Put a modern timing light on it
and adjust the vernier on the mag ( by undoing it and turning it) until the
mark on the vernier on the motor side is back to 12 o'clock
Provided that you
have been careful to measure the 8.75mm your motor is perfectly
timed
Now put a mark right
across the whole coupling block so that if you lose your timing for any reason
you can easily pick it up again
r
........................................................................................................................................................................
6)Dont
toss out worn kingpins, they can be ground down & undersize bushes fitted
and hand reamed. On my sedan, one side has been ground 10th and the other
8th
