Dollar injection. Pound injection works well in some parts of the world.

There's not a lot left from front drums that is useful when you convert
to disks.

Where are you? This will affect parts availability and pricing.
What is the Mini? How old is it? Do you have 10" wheels?

Minis have been factory fitted with at least 3 different types of disk
brakes over the years.

The Mini Cooper of the early 1960s with a 997 or 998cc motor had
revolutionary 7" diameter, 1/4" thick disk brakes. They're really not
much improvement over drums, though you don't have to adjust them every
wednesday. They're rare as hen's teeth and if you tripped over a pair at
a price you can afford, you'd be better off selling them to a concourse
enthusiast and buying one of the alternatives.

The Mini Cooper S (970, 1071 and 1275cc) of the early 1960s through to
the early Clubman GTs (1275cc) of the early 1970s used 7-1/2" disks,
3/8" thick. These fit under 10" wheels and are fairly expensive.

Later Clubman GTs and eventually all Minis built after about 1984 got
12" wheels and 8" disks. In the UK these are plentiful and relatively
cheap. In Australia they're found in late (1977 on) 1275 Californian
Mokes (but not 998) and in the limited model Clubman 1275LS which was
built in 1978 to run out the last Mini body shells. They're perhaps a
little cheaper than CooperS disks in Australia, but you have to find
some 12" wheels to fit over them, and convince your insurance company to
cover the 12" wheels.

IMPORTANT STUFF

Both the Cooper S 7.5" and the later 8" disks give less braking power
for a given brake line pressure than drums. You have to push the pedal
harder. A booster reduces this effect.

To prevent the rear wheels locking when you apply more force (because of
the front disks) you MUST replace your 3/4" diameter rear wheel
cylinders with 5/8" front disk brake type rear wheel cylinders. If you
do not, the first time you try to stop in a hurry on loose gravel or wet
roads, you will lock your rear wheels and find yourself facing the way
you came from.

THE CONVERSION:

I believe the drive shafts and inner CV joints are the same. Both 7.5"
and 8" disks use the same outer CV joint and hub, which is different
from drums. The caliper, pads and disk are specific to each disk size.

Your best bet is to buy complete front disk assemblies from bottom
balljoint to top balljoint, including the CV, the brakes, hoses, etc.

METRO BRAKES:
The Metro disk brake hub is taller from bottom ball joint to top ball
joint. If you fit a Metro hub, the lower balljoint will be too low, the
lower arm will tip down too low, and hence closer to the centreline of
the car. The front camber will be far to positive and the handling will
be horrid.

In the UK, but not in Australia, there is a good deal of activity
converting various Metro brake parts to use Mini hubs. You need to know
what you are doing or buy from someone who does.

MORRIS 1100/1300 BRAKES:
I know of a Moke (13" wheels) in Australia which uses Morris 1100 disks
and calipers on drum brake hubs and CV joints with an aftermarket
adapter plate. These brakes obviously won't fit under 10" wheels. I do
not know who built the adapters or if they are/were commercially
available. I do know that Australian state registration authorities
would want an engineers report for such a conversion, whereas Cooper S
or 8" disks are accepted as standard parts.

ts pretty straight forward, cheapest way is to fit the disc setup from
mini's with 12" wheels (anything after late '85?).
You will need the complete hub assembly with disc & caliper, a new set of
braided hoses wouldn't go amiss while your under there either.
Alot of people take the driveshaft too and just pop it into the existing
inner driveshaft joint.  Saves messing aroung with CV rubber boot on hub.
Car will need tracking done after fitting.
To go the whole hog, widen the track at the rear by fitting spacered drums
with longer studs.

chris

What vintage drums?

If "early" I'd just get an upgrade to twin-leading shoe drums (at about
$300). They are a MIGHTY improvement over the original single-leading shoe
ones.