Engine
Transplants
In
New Zealand, the most common engines fitted to Minors are
the Morris Marina 1300 and the Datsun
1200 engines, although, the much more modern and powerful
Toyota 4A-GE Twin Cam 1600 engine is
making an impression on the Modifying scene.
In
the UK a very popular engine swap is the Fiat
Twin Cam.
Another
engine making an appearance on the transplant scene is the
Rover K-Series twin cam engine.
It's available in 1100, 1400 and 1800cc sizes and there's
a kit being produced by the likes of JLH Minor restorations.
Toyota
4A-GE
If
you're looking for high-revving POWER in your Minor then this
must be one of the best available options. The engines come
from the rear-wheel-drive versions of the Toyota Corolla range,
dating from about 1983 to about 1988. The engine fits surprisingly
well into the Minor engine bay. It's almost exactly the same
length as the Datsun 1200, maybe even a little shorter (the
ancillaries like water pump and fan blades stick out less).
The
4A-GE puts out around 110bhp in standard form, so if you follow
this path you should expect to have to change the rear axle,
and obviously the brakes all 'round. The poor old Minor diff
just wont take the power and the front drums are hopelessly
inadequate for slowing a car rapidly down from a possible
top speed of around 130mph/200kph !
The
choice of differential is up to you, but the humble Vauxhall
Viva does an excellent job of coping with the standard power
output of a 4A-GE. If you are looking for more power, then
think about buying an entire RWD donor Corolla. Buying a donor
car will ensure that you get all the right bits, the diff
will be designed for the engine, and with a bit of prudent
shopping around, you may even get a disc braked rear end.
For these try finding a Trueno or Sprinter (model names may
differ outside of NZ).
If
buying the engine & box by itself, make sure that you
also get ALL of the plumbing. This includes all wiring from
the engine back to the plug fittings, the electronic ignition,
fuel injection unit and the 'Black Box'. The Box is VERY important,
'cause it's this that controls all the electronics, ignition
timing, knock sensor etc etc. Buying a Box by itself later
could prove expensive.
Fitting
of the engine, gearbox and new diff should probably be performed
by a professional. Fitting a new diff involves manufacturing
new spring & axle mounts, and the WOF/MOT men will look
closely at the work done.
My
advise when it comes to welding important bits - Let Someone
Else Do It!
Even
MORE Power!
The Toyota MR2. Toyota's mass produced 'Sports' car. 1600cc
Twin Cam. 130bhp in standard form. Plenty you say? Want more?
SUPERCHARGE IT!
The
4A-GE is also available in Supercharged form, as in the 4A-GZE,
as fitted to the MR2. Fit one of these babies into a Minor
and you'll have one awesome piece of machinery! I have yet
to see one in-the-steel, but I'm sure one can't be far away.
The 4A-GZE puts out around 150-160bhp. These engines also
perform well if converted to use 'Old-Style' carburetors.
An Off-Roading friend of mine removed ALL of the electronics
and fuel injection, made up a casting to accept a Holley 350
carburetor, fitted a smaller supercharger pulley and locked
it in place so that it operates at all engine revs giving
about 15 pounds boost at all times! Driving through a VW gearbox
(the engine sits in the back of the Off-Roader) it dynoed
at 160bhp AT THE WHEELS!
Fit
a 'GZE to a standard-looking Minor and you have an awesome
Sleeper!
Datsun
1200
The
Datsun A-series Engine
Believe it or not, the Datsun 1200 is actually very closely
related to the Austin/Morris A-series engine. The Datsun A10
engine was rated at around 1000cc and apart from superior
manufacturing and machining processes, was in fact a clone
of the good old 850 and 948cc engines of the late 1950's.
The
Japanese, with their know-how of taking a good idea and making
it great, transformed the ageing BMC lump into a fairly good
performing, high(ish)-revving engine of 1170cc. This powered
a range of Datsuns from the early 1200 series of cars through
to the 120Y and Sunny family-cars.
When
transplanted into the Minor, the slightly lighter body and
the lower ratio differential results in a liveliness from
the Datsun 1200/120Y engine that hadn't previously been seen
in it's mid-size vehicle incarnation.
A
Datsun-powered Morrie is a Morrie transformed; capable of
cruising happily at 115kph/70mph all day, and even 170kph/105mph
with little modification.
Which
is Best - 1200 or 120Y ?
It doesn't really matter which version of the engine you get,
although you should probably go for as late a model as possible,
simply because it's far less likely to have done HUGE numbers
of miles. That said though, it's still fairly easy and cheap
to fit new rings and bearings to all of the Datsun engines,
and you'll probably want to do that as a matter of course
once everything is set up for your Minor.
Fitting
the Engine and Gearbox
There is a subtle difference between the blocks of
the 1200 and 120Y, and this is in the area of engine mountings.
Depending on which block you have, when using Ford Escort
or Cortina engine mounts, the engine will sit either WAY
down in the engine bay, or will be lopsided. Both cases will
mean when fitting the engine mounts to your Minor you will
have to weld the mounts on top of an 'n'-shaped piece of thick
steel (preferably at least 3mm thick).
When
fitting the engine and gearbox, you may also find (depending
on how high the engine is placed in the engine bay) that the
top of the gearbox fouls on the Minor steering rack. This
is easily fixed by shaving some of the excess aluminium from
the ridge that runs down the top of the box'. In extreme cases
you may have to actually cut a hole in the top of the 'box.
Don't worry, the 'box is not load-bearing and wont collapse
(not unless it's a really HUGE hole, in which case
there's something wrong with your setup elsewhere!!). If you
do end up opening a hole in the box, you may like to think
about cutting out a piece of sheet aluminium and riveting
or glueing it over the hole to keep dirt and grime away from
the clutch mechanism.
When
positioning the engine in the engine bay, it will be necessary
to push the engine as far back in the engine bay as possible
in order for the fan blades to clear the radiator. DO NOT
DRILL HOLES OR WELD THE ENGINE MOUNTS IN PLACE YET !!
Mark
out where you think the engine mounts should be positioned,
but this may have to be shifted slightly when fitting the
gearbox cross member and the drive shaft.
Gearbox
Cross Member and Drive Shaft
Depending on the type of engine/box you have, you may be able
to use the original Minor gearbox Cross member. The later
model Datsun 120Y engines had the Cross member mounting positions
located further back on the gearbox than the earlier 1200-series
engines. These later gearbox mountings are in almost exactly
the right spot for bolting to the existing Minor Cross member.
Just a couple of extra long bolts and a rubber bush is required
to secure the gearbox in place. At this stage I recommend
you offer up the Datsun drive shaft to the Minor diff'. It
should bolt up directly to the Minor diff', although you may
require slightly longer bolts.
Fit
the nose of the drive shaft into the back of the gearbox and
adjust the position of the engine & 'box so that there
is 15 - 20mm of slide movement on the drive shaft splines.
This will then give you the required position of the engine
mounts. Of course this may have positioned the engine too
far forward and the fan blades will foul the radiator. In
this case you will either have to fit an electric fan (I suggest
in front of the radiator, behind the grill slats), or find
yourself a thinner core radiator from a late model vehicle
(the standard Minor radiator does an excellent job of cooling
the water, and a thinner one shouldn't provide any significant
cooling problems. If you're worried, you may like to fit an
extra-wide radiator).
Clutch
Linkage
You can leave the clutch linkage as-is on the Datsun 'box,
but this will result in the lever exiting the 'box high up
on the driver's side against the floor pan. If you cut a slot
diagonally opposite the current lever slot in the bell housing
and rotate the clutch release fork and lever 180 degrees the
lever will exit the bell housing at the lower left (passenger
side). You will have to build up a pivot point in the bell
housing for the clutch fork/lever and also drill and tap two
holes in the outside of the bell housing to accept the clutch
cable bracket. There is a convenient flat casting in exactly
the right spot for this. You will also have to make up a bracket
to hold the clutch cable in place. This only needs to be a
simple 'L' shape, but you should make it out of 2mm thick
steel, at least.
Well,
that's the basics of it. I know there's a few murky bits in
the text, but because of the infinite number of combinations
of engine, gearbox, drive shaft, engine mounts and Minor models,
it's impossible to know exactly what you require.
In general, you can expect to have to fit and remove the engine
and 'box at least half a dozen times before you get
everything in the right place.
Maybe
it's easier to get someone else to fit it ... ?
:)