Installing a rear subframe in a Classic Mini

Question: Has anyone bought and installed an MS45D aftermarket rear frame? I’m needing to replace the rear frame on Mrs. Mad Dog’s Mayfair and was wondering if the aftermarket unit is a suitable substitute. If anone has installed one of these and have some comments they’d like to share, please let me know.

Answer: I’m not sure if it was this rear subframe or another that I installed, but ANY rear subframe will have it’s trials and tribulations and generally not because of the subframe itself but because of the rust in the parts you are trying to remove and/or reuse. The trunion bushings allow for a bit of manufactured misalignment, so shaving some here and there will allow you to compensate for gross errors. The errors in tracking or toe, which you would have in probably any Mini Cooper subframe you use, can be corrected with shims and files (if you’re patient and have a lot of time on your hands) or with the adjustable rear brackets (which could speed up the process some or even actually add more time because of filing/grinding you’ll have to do to get them to fit with your existing parts).

I advise you to be prepared with helicoils for the heelboard mounts, completely new hardware, a complete section or splice of hard brake line and possibly fuel line as well, new flexi lines (while you’re in there) and that short section of hard line that mates up to the rear slaves, new rear brake cylinders (again, since you’re in there), new trunion bushings, and possibly new rear pins. Also jack up and inspect the swingarms for play because if there’s play you may as well take care of it all at once.

If everything went perfectly, it would just be under a couple of hours; chances are it will be the better part of an afternoon or weekend, though.

Thanks: Mike Spangler

Mini Pick-up on the way to a Vtec Conversion

The Mini pick-up that has been in the family for the last 20 or so years is now finally at the body shop for the first step on the road to being converted into a Vtec powered monster. I gave this pick-up many years ago to my first daughter to learn how to drive in (and get her first speeding ticket). She drove it a number of years until it was not big enough for a family, then it was handed off to my son who drove it as a daily commute car for many years. Finally it landed back in one of my garages where it has set for the last almost 10 years! It will not be rebuilt as a personal toy for use only (maybe).

Can I use your waxoyl kit to to the underside of my Mini?

Question:
Can I use your waxoyl kit to to the underside of my Mini Cooper? I want to do the whole underside and the complete inside floor, any idea of how much I would need?

Answer:
The kit, part number WAXOYL is available from Mini Mania and it should contain more than enough to do what you want.  I suggest you do the underside first and then see how it looks and feels. You may not want to cover the inside floor.

A good place for the Waxoyl is inside the sills. This may require drilling an access hole.

How to Identify Your Mini?

When is a Mini, is a Mini, is a Mini? Most current or potential Mini owners have no idea how to tell what kind of Mini they have. In fact, in many cases they don’t even know there are really so many different Minis.

The first Minis were released to the public in 1959, and while the same basic car was produced for 41+ years, the differences from start to finish were very dramatic. The first Mini was the ultimate in an economical everyday, entry level car. By the end of production it had been transformed into an almost modern car with fuel injection, catalytic converter and air bag. Needless to say, all Minis were not created equal, and in fact, have tremendous variation in performance and desirability.

The Mini was only sold in the USA from 1960 thru 1967! The very first cars were powered by 848cc BMC A-series engines. The same basic engine configuration found its way into many of the entry level British cars of the day. Everything from Morris Minors to Bugeye Sprites all had this basic engine design. So you ask, why all the confusion as to what Mini you might own or consider buying?

As a first consideration, let’s simply address those variations as imported and sold by the factory. The most distinguishing feature of all models from 1959 through 1967 was the use of sliding window doors. These windows slid fore and aft in the doors that also featured external, visible door hinges. The very first cars were simply called Minis and all were supplied with the bullet proof (but slow) 848cc engine. The first of the models to be identified as Mini Coopers were introduced in 1961 and were powered by a 997cc engine. The Cooper designation was continued as the engine evolved to a much different and better 998cc one. The first of the Mini Cooper S models was introduced in 1963 with a tremendously upgraded 1071cc engine (the choice of displacement was driven by race class considerations as was that of the very rare 970cc S engine). The most common and sought after model of the Mini Cooper S was introduced in 1964 with a 1275cc displacement. This is the same displacement as used on the car when production finally ceased in the year 2000. The final year of factory sales in the USA saw the introduction of the Mk II version of the range that featured, among other smaller cosmetic changes, larger tail lights. The only other significant variation is that the first of the Minis all had drum brakes at four corners, but starting with of the Mini Cooper, the Cooper and Cooper S had disk brakes at the front. All models used 10” diameter wheels of various widths. You could easily argue that if that were all we had to consider when owning or buying a Mini today, it would be too easy. But the current appetite for a Classic Mini in the USA has pushed the market way beyond those cars imported by the factory. At this date in time it is easy to admit that more Minis have been imported into the USA by private parties and private dealers than were ever imported by the factory. And the problem is knowing what the Mini really is. The factory produced over 5,000,000 during it 41+ year production run. Less than 15,000 of these were imported by the factory into the USA. So what really is the Mini that has been imported by the aftermarket?

The problems start from 1968 on when the factory no longer attempted to have the Mini of any configuration conform to current emission or safety standards. Now, Federal law allows models at least 25 years old to be imported into the USA without concerns for these standards. Thus, the next pool of “legal to import” Minis are those produced from 1968 through 1981. These models start with the Mk II found with 848, 998 and 1275cc engines. By late 1969, the models known as the Mk III now featured roll-up windows and internal door hinges. By1973, the electrical system was upgraded to include the use of an alternator to replace the generator. And the use of a “rod change” transmission to replace the “remote” and “magic wand” transmission began.

In 1976, the range was further upgraded to the Mk IV. The most significant change was not very visible as it was an attempt to isolate the car from road noise and involved using rubber mounts for the front subframe. In 1980, the most obvious change was the introduction of the “Verto” clutch system. Again, not an outwardly obvious change but significant none the less. The year 1984 saw the introduction of the Mk V Mini models that are most notable for the standardization of the use of 12” wheels and bigger disc brakes. The various changes after the Mk V seem to come fast and furious. The Mk VI is generally around 1991 with a number of variations. The 998cc engine was discontinued in 1992. The introduction of a ‘single point fuel injection’ system to replace the single 1¾” SU carb took place in the same era and it continued through 1996. For the final years of production the most significant changes included the use of a ‘multi-point fuel injection’ system along with many modern features: such as, alarm systems and catalytic converters.

So what year is the Mini in question? These were also hundreds of other changes and more subtle ways to determine the year and model of the Mini. For an extensive detailed review and interactive pictorial visit the Website www.Minimania.com/MiniID

Decoding Modern Car VIN Numbers

The 17 digit VIN began in 1981 and continues to present.

Understanding your vehicles serial (VIN) number

1st character- Identifies the country in which the vehicle was manufactured.
For example: U.S.A.(1or4), Canada(2), Mexico(3), Japan(J), Korea(K), England(S), Germany(W), Italy(Z)

2nd character- Identifies the manufacturer.
For example; Audi(A), BMW(B), Chrysler(C), Dodge(B), Ford(F), GM Canada(7), General Motors(G), Honda(H), Jaquar(A), Lincoln(L), Mercedes Benz(D), Mercury(M), Nissan(N), Plymouth(P), Toyota(T), VW(V), Volvo(V).

3rd character- Identifies vehicle type or manufacturing division.
Chevrolet(1), Pontiac(2), Oldsmobile(3), Buick(4), GM Overseas(5), Cadillac(6), GM Canada(7), Saturn(8), GM Overseas(9), Chevy Truck (C), GMC Truck(T)

4th character- Identifies the restrain system.
Non-passive(A), Automatic belts(B), Inflatable restraint(C)

5th character- Identifies the series.
Chevette CS trim(B), 2WD Truck(C), Cavalier base trim(C), Cavalier CS trim(D), Cavalier type 10(E), Van(G), Citation(H), 4WD Truck(K), Chevette base trim(J), Impala(L), Camaro Sport Coupe(P), Step Van(P), Caprice Classic(N), Camaro Berlinetta(S), Small Pickup(S), Malibu(T), Malibu Classic(W), El Camino(W), Celebrity(W), Citation(X), Monte Carlo(Z)

6th and 7th character- Identifies the body style.
Landau Coupe(03), 2 dr Coupe(08), 1/2 ton(10), 2 dr notchback Coupe(11), 4dr Sedan(19), 3/4 ton(20), 1 ton(30), Sport Coupe or Convertible(27), Station Wagon(35), Sport Coupe(37), Sport Coupe(47), 2-1/2 ton(50), 3 ton(60), 4-1/2 ton(65), Convertible(67), 4dr Hatchback Sedan(68), 4dr Sedan(69), 2 dr Hatchback(77), Sedan-pickup(El Camino)(80), Sport Coupe(87)

8th characters- Identifies the engine.

9th character- is a check digit to verify VIN accuracy.

10th character- Identifies the model year.
For example: 1981(B), 1982(C), 1983(D), 1984(E), 1985(F), 1986(G), 1987(H), 1988(J), 1989(K), 1990(L), 1991(M), 1992(N), 1993(P), 1994(R), 1995(S), 1996(T), 1997(V), 1998(W), 1999(X), 2000(Y), 2001(1), 2002(2), 2003(3)

11th character- Identifies the assembly plant for the vehicle.
Lakewood(A), Baltimore(B), Lansing B(C), Doraville(D), Linden(E), Flint (Chevy)(F), Framingham(G), Flint (Buick)(H), Janesville(J), Kosai(K), Leeds(K), Lansing(M), Norwood(N), Pontiac (Pontiac)(P), Detriot(Q), Arlington(R), St. Louis(S), Ramos Arizpe(S), Tarrytown(T), Hamtramck(U), Pontiac (GMC)(V), Fairfax(X), Wilmington(V), Fremont(Z), Wentzville(1), Oshawa #2(1), Moraine (T&B)(2), St. Therese(2), Detroit (T&B)(3), St. Eustache(3), Orion(4), Bowling Green(5), London(5), Oklahoma City(6), Lordstown(7), Shreveport(8), Fujisawa (Japan) Luv(8), Detroit (Cadillac)(9), Oshawa #1(9), Pontiac (GM Truck)(0)

12th to 17th characters- Identifies the sequence of the vehicle for production
as it rolled of the manufacturers assembly line.  Starting with 100001.

PS- Not certain if any of this applies to Mini Coopers?

Spax Shock Settings

My shiny new SPAX shocks arrived yesterday. I’m wondering about the setting, since they are adjustable. I am running the green coil springs, which are pretty stiff.
__________________________
Aren’t the green suggested for racing? I have found for autocrossing that the blue springs with my Spax 5 clicks from softest works best. Best to start at the min setting and see how the car handles in turns and over your usual road surfaces.
__________________________
Turn ccw for softer and visa versa. You will feel the adjustment thumb screw easier to turn as you go in the softer direction.
_________________________
Thanks… I knew they had been set pretty stiff, so I turned them CCW, assuming that like most adjustments, CCW is lower, like on a volume control. I only turned them 3 clicks, so that is probably why it didn’t seem like much of a change. Was kind of afraid to turn them too far. I don’t really have a problem with the setting, but my wife isn’t too fond of the stiff Mini suspension. Even at the softest setting, the Mini doesn’t have a squishy “luxury car” ride, but that’s one of the things which makes them handle so well and be so much fun! In the spring I’ll play with the settings and see what kind of mid range I might find. (Didn’t even think about looking in the tech pages in this Mini Cooper site!)
_____________________________________
I can’t speak for the latest generation of Spax, but they used to be notorious for being stiff. Street settings with cones were 1/2 or less on the front and dead soft on the rear. It was easy to get them too hard. Depending upon your use, start soft and work up.

Mini Cooper S Brake Caliper Pistons

As far as cutting air slots in the caliper pistons, you don’t want to cut slots so deep that they could uncover the piston seal when the piston is pushed all the way in, that is the limit for the slot depth. The pistons in the picture above have four cuts, I would guess this gives about 25% reduction in surface area touching the pad. The slotting shown above looks shallow enough that those pistons could probably still be used with dust seals. This could be OK, but more slots will reduce the surface area further, and offer more paths for cooling air. I just mill flat-bottomed slots, my suggestion is 8 slots so you get around 50% reduction in area touching the pad. (From Mini Cooper Message Forum)

I took another look at Tarzwell’s Competition Mini book last night, he has more good ideas in his brakes chapter. Among other things, he suggests: air ducts

pack the piston with stove insulation, capped with a stainless lid

stainless sheet between piston and pad

reflective stainless heat shield between rotor and caliper

polish backing plate of brake pad

ceramic paint on caliper

machine grooves in caliper

open up caliper bridge to increase air flow to pads/pistons

Mini Cooper Air Temp Sensor

dont know if this will  help but here is an clip from http://www.gaima.co.uk/peter/RoverMEMS.pdf

“The ATS is mounted in the air inlet casing (MPi) or air filter casing (SPi), and measures the air temperature before it enters the inlet manifold. Because the density of air varies in inverse proportion to the temperature, the ATS signal allows more accurate assessment of the volume of air entering the engine. The open-circuit supply to the sensor is at a
S.O-volt reference level, and the earth path is through the sensor return. The ATS operates on the NTC principle. A variable voltage signal is returned to the ECM based upon the air temperature. This signal is approximately 2.0 to 3.0 volts at an ambient temperature of 20°C, and reduces to about 1.S volt as the temperature rises to around 40°C.
Although the air filter casing used on SPi models contains a thermal valve system, the thermal valve has no bearing on the AFR, and the air temperature is calculated solely by reference to the ATS.

Building a BMC A-Series motor for street or race!

We have all seen the tremendous number of cars still being used as vintage race cars and/or street cars that still run the venerable A-Series motor that was first introduced in the late ‘50s.  These motors were used in everything from Sprites and Midgets to Morris Minors and Mini Coopers.  Many of these motors found their ways into any number of special race cars including the early Lotus 7 and many Formula Juniors.  The motors ranged in size from the first 850cc (actually 848cc) found in the 1959 Minis to the most common 1275cc as used in the later Sprites and Midgets (the last of these models actually converted to the 1500cc Triumph engine). 

So with all of these potential applications, it is easy to see why so many are always being rebuilt for street or race applications.  The simplicity of the motor not only made it so universal in it’s applications but also means that everyone that has one would like to believe that they can at least manage the rebuild process.  While some people are satisfied with simply understanding the process and will have a professional do the actual work, other at least want to identify the various upgrades options they want used.  And still a large number of people want to do all but the machine shop work themselves.  This means that information is the best tool that we all need before we attempt this ‘simple’ project.

The first step is to determine what type of owner you are going to be?  What are the pros and cons of being the total do-it-yourself person. If you have rebuilt a motor of any type in the past then it is an easy answer- have at it- these are indeed simply motors. You will indeed benefit from having the advice of someone that has done one of these motors in the past, but on the whole you only have a few technical features that could be considered unique to these motors that you might benefit from.

If you decide that while you think you know what you want as an end result but lack the desire or skill to do it your self, then researching all the books written and various Websites dedicated to this motors is your first step. Now this process could be a lengthy one if you have not previously tried to understand how to pick a camshaft, decide on carburetion, etc. etc.  Lot’s of expert advice would be a big help. 

If you really want the easy way out, contact your local builder, tell him what you intend to do with the motor and let him have at it.  But here is the first word of caution! Just because your local builder has been building Chevy motors for a gazillion years does not mean he can build even a street motor yet alone a race motor.  A few simply questions could go a long way to try to qualify your choice of engine builders.  Has he ever build a BMC A-Series motor or any British car motor?  Does he know where to source the parts he/you will need?  Under no circumstances should you entrust a race or performance motor to an engine builder that can not answer yes to all of the above question.  If you are looking for a good street motor, I would suggest that at least the shop should have worked on British motors before you entrust him to ‘try his luck’ on yours. 

If you are planning on building the motor yourself, many of the same questions apply to how you will pick a machine shop to prep your block, crank and cylinder head.  If the shop ask you for the clearance to set for the connecting rods- take it someplace else!  If the shop ask you to supply the valve seats- take it someplace else!  If the shop does not understand the tricks to line hone an inline (Sprite/Midget) block- take it someplace else!

 

 

 

 

 

 

 

 

 

Mini Cooper Speedo drive compatibility

Altering the final drive in a Mini Cooper can cause speedo inaccuracies. Whilst being a possible excuse for transgressing speed limits, it probably won’t keep you out of traffic cops notepads. This therefore needs attention.

Prior to 1980, matching FD changes to speedo readings was done by fitting a different speedo, an expensive way of dealing with the problem. After this the mix ‘n’ matching went on in the gearbox. More specifically the speedo drive spindle and pinion. So dealing with the easiest one first, fitment of any A+ gearbox with a 3.44 FD to a pre-A+ powered Mini, you need to fit the spindle and pinion out of the pre-A+ gearbox. Simple. If any other FD is fitted, it is easier and cheaper (in the long run) to get the speedo re-calibrated. Now the multiple choice option…check out the relevant table. This assumes 10” wheels and 12” wheels are retained where fitted as standard, but is reasonably accurate for 13” wheels, as the rolling circumference is very similar.

Speedo drive spindle and pinion data -