BMC Mini

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Do you drive this great classic or are thinking of buying one? Here’s how to ensure that you get the best out of yours for years to come…

Perhaps one of the world’s most often modified and tuned cars, the original Mini came a long way from the 850cc Basic and Deluxe models launched in August 1959, to the final Cooper Sport that rolled off the production line in October 2000. Today, there’s plenty you can do to modify and upgrade a Mini of any age and ther’es no shortage of spares and bits, so our guide is just a basic overview. For the DIYer, the Mini is simple to work on although rarely pleasant due to the tight confi nes. Working on a’wet’ suspension still requires care, especially when draining the high pressure fl uid - like when dropping the dreaded rear subframe to replace it. 

1 ENGINE OUTPUT

Mod The original 850cc engines produced just 34bhp, but the stroke was lengthened for the fi rst of the Coopers, resulting in a 997cc unit that produced 55bhp. This was later replaced by a 998cc unit, with Coopers also featuring 970cc, 1071cc and 1275cc engines. The 1275cc unit is probably the best starting point for tuning, but all can be made to run better. Tuning generally starts with a basic Stage One kit for around £150, generally consisting of a modifi ed inlet manifold, exhaust manifold, exhaust, air fi lter plus where it’s needed a new carburettor needle. This will typically give a 15 per cent improvement in performance.

Mend Due to interchangability, its easy and wise to uprate a Mini’s engine when it’s being rebuilt. For a stock head replacement, you could look at fi tting the head from a Cooper S, 1300GT or Metro turbo. Cheap mod on most is to rejet SU carb with richer needle and sports air fi lter. Most engines ‘rock’ and cause clutch judder, so check stabiliser bar and keep eye on the engine mountings.

  2 BOTTOM END

Mod It’s possible to take a 1275 out to 1380cc. Some fi t MG Metro engines but it’s tricky and you’ll have to modify the cooling system. From Minispeed, a 1293/1330cc fully-rebuilt unit, with a Stage 4 head, reground nitro-carburised crankshaft etc costs £2797.

Mend Change oil every 3000 miles as its shared by transmission. Bore and cranks wear. Timing chain rattle is fi ddly but cheap to cure. Oil leaks impossible to stem…

  3 FRONT SUSPENSION

Mod Instead of replacing with standard components, you could consider fi tting adjustable suspension, with companies such as http://www.minisport.com selling adjustable suspension kits. From Mini Sport, the Sports Suspension Kit with Spax adustable shock absorbers currently costs £227.80.

Mend Old rubber cones can be replaced, with standard units from http://www.minisport.com costing £32.72, while uprated competition units cost £45.78. Clicking when on full lock signifi es work cv joints. MK II cars had different steering rack and needs MK II arms to fi t earlier car. Keep top swivels well greased. It’s becoming harder to fi nd garages with pumping equipment to reset Hydrolastic suspension; can be converted to ‘dry’.

  4 BRAKES

Mod Some owners fit the four-pot vented disc set-up from the Metro Turbo, which can be fitted to the standard caliper-type Mini hub. http://www.minispares. com sells a Metro Turbo vented disc front brake kit for £297. Just uprated pads works well for general motoring.

Mend Amazingly disc brakes only became standard in 1984; alloy fi nned drums ok substitute. Rear handbrake quadrants seize on cars rarely used.

  5 GEARBOX AND AXLE

Mod You can add a bit more speed by fi tting straight cut gears to your box, since also they reduce friction but do add to noise levels. You can pay up to £600 for a straight cut gearset, and they are often sold as close-ratio sets. Last of the line model used highest axle ratio to aid cruising – or fi t larger rims for similar gain. If your gearbox is worn out, it might be worth upgrading.

Mend Specialists such as http://www.guess-works.com can supply units with modifi cations such as straight cut gearsets and drop gears. Prices start at £550 for a standard gearbox, up to £1315 for a modifi ed box. Minispares sells new close ratio kit for under £200.

  6 BODY AND CHASSIS

Mod The great news with the Mini is that everything is available to practically build your own car from scratch if you wanted to, with only some panels for early models being harder to source. For instance, you can buy a complete (MK V only) Heritage bodyshell for £4650, or £4800 for the Clubman.

Mend Repairing a Mini is a constant battle against rust, and it’s an awkward car to repair on a DIY basis. Usual rust areas include the rear subframe (last on average seven years if untreated), sills and fl oor panels. New subframes are cheap to buy if not fi t, with a new Heritage rear subframe costing £325. Traveller wood isn’t structural but dear to renovate; look for spliting metal on rear door apeture and door fames crack.

  7 PANELS AND TRIM

Mod There’s enormous scope to upgrade the interior trim of any Mini; how about a burr Walnut dashboard for starters? Minisport supples a range from £111.

Mend I Many specialists offer original-style replacements. Even the very early models are catered for, with Newton Commercial, for instance, selling a pair of interior door trim panels for a MK1 Mini for just £53.78.

  8 ROLLING STOCK

Mod   Famously started off with tiny 10-inch wheels, but 12-inches became standard on later cars. You can choose from a huge range of posh wheels, such as 5x12 Revolution wheels, which cost £67 each from http://www.minispares.com. You can still buy 5x10 Minilite-type wheels (not exact originals), which cost £82 each, from http://www.minispares.

Mend Fitting larger tyres from later Minis isn’t as easy as it sounds, especially 13inch types. Coopers S rims usually require spacers. Greasing radius arms often forgotton. Subframe renewal is a major job and usually unearths rot.

  9 REAR SUSPENSION

Mod   Try the Moulton Smootha Ride kit, which http://www.minisport.com markets as a package with its Adjusta Ride system for £275, for a complete front and rear kit. Fitting a rear anti-roll bar in isolation to cure understeer makes car very twitchy.

Mend Simply replacing the worn out rubber cones and shock absorbers at the rear makes a huge difference. Standard replacement cones cost around £33 each, with uprated ones around £45 each (www. minisport.com).

  10 ROVER MINIS

These later Minis are broadly similar to look after but there are differences. EFI models feature single point injection with MEMS engine management. CAT cars have special pipe work but the rear section is virtual MK III Cooper S. Rear brakes are Cooper S on all cars. Just because it’s a Mini, don’t think that parts are instantly interchangable with earlier cars – they’re not! Post 1995 cars had front mounted rad (at last!) while unleaded cylinder heads were not fi tted until 1989.

    SERVICING TIPS

Engine oil (20W/50 or 60); 8.5 pints Gearbox Shared with engine Cooling system 6.5 pints Spark Plugs Champion N9Y (N5 Cooper) (or equivalent) 0.020in C.b. points 0.014-0.016

Timing 8-15 degrees BTDC*

Valve clearances 012in (in/ex)*

* Varies according to year/model

  BUYING TIPS

Amazingly, Mini’s aren’t the easiest of cars to vet and originality, especially on older vehicles is unlikely to be kept. Rust is the biggest worry on all of course as well as subsequent bodging. Engines are tough but transmissions aren’t. Van and pick-ups soaring in value – not so the post 1990 Coopers which lag behind originals yet in many ways are the better cars.