The quest for power has always been a popular pastime, but never has it been quite as widespread as during the years since the inception of Alec Issigonis’ ADO 15. The Mini has since become an institution in itself, but, more important, it has provided the tuning concerns with extremely pliable basic material. One has only to look in on a race meeting, rally or what you will and evidence of the Mini’s popularity among competition drivers is readily apparent. But Mini tuning does not stop at competitions. Improving the breed has become almost a fetish among all Mini owners and an absolutely standard version is a relative rarity on the roads.
With this in mind, we decided to take a look at the most potent of the Minis, the 1,275 c.c. Cooper S, tuned to a degree which does not render it unmanageable on public roads. The car we opted for was the Speedwell version, designated 1300 TC, the letters being taken to mean “Ton Car.”
At their Finchley workshops, Speedwell Performance Conversions suffer from a space scarcity, but they have indeed worked wonders with the little that is available. Not only do they have a comprehensive stores set-up, but a fully sound-proofed engine test bed and an array of rigs and machine tools that would be the envy of many a concern ten times its size. Mass production techniques may well be used for the manufacture of parts, but machining and installation is very much an individual affair. This personal attention to each unit, coupled with excellent engineering facilities, is certainly felt when the finished product is tried. Collecting the test car was a pleasure. Not only was it clean, both inside and out, but it was brimful of petrol to facilitate a consumption check and the boot contained a few odd spares such as plugs, gaskets, fanbelt etc….”just in case.” The case never arose, and the only troubles we had in almost a fortnight with the car were a door bolt which would not pop out after being opened and a side-lamp bulb holder which came away from its socket, both of which were remedied quickly and simply.
Much of the work done on the 1300 TC has been in the engine compartment, with the result that over 90 b.h.p. is now available at 6,500 r.p.m., and 87 b.h.p. in the range, 5,500 to 7,000 r.p.m. Torque peaks at over 85 ft. lb, at 5,000 r.p.m., but 70 ft. lb. is available from 1,500 to 6,500 r.p.m. and over 65 from 1,000 r.p.m., indicating a useful torque curve.
On receipt from B.M.C., the engine is stripped and all rotating parts are dynamically balanced. Reciprocating parts are hand balanced. The cylinders are bored to a capacity of 1,292.8 c.c. and the numerous modified parts fitted. These include a chromemolybdenum steel crankshaft, solid-type pistons with high speed rings, a Speedwell camshaft driven by a duplex chain, Nimonic valves with double springs of Swedish steel and high lift rockers. The head is machined and polished and the inlet manifolding is hand matched and similarly polished. A lightweight flywheel is fitted and twin S.U. type H4 carburetters with no air cleaners.
The gearbox is the standard Mini-Cooper unit with a 3.44 final drive ratio.
Other equipment includes an oil cooler, a brake servo, laminated windscreen, twin fuel tanks (a single 5 1/2-gallon tank was fitted to the test car resulting in a rather limited range), and a sump guard.
Unlike other tuned cars, the 1300 TC really lived up to its Town Car designation. In heavy traffic it was neither fluffy nor temperamental and was possessed of a high degree of tractability. It is indeed rapid through the gears and, as I am accustomed to the relative sponginess of an Austin 1800, it did much to restore my faith in the transverse engine-f.w.d. layout. Mini drivers are said to be a breed. I have never believed this but the car is such a wonderful town machine that I found myself getting into scrapes, which is the price one pays for swapping a big car for a small one and overestimating its powers of traffic penetration, but this was a driver fault and nothing to do with the car. Stationary in traffic, the thermometer needle crept slowly up but never went beyond 90’C. and quickly dropped after only a short burst of speed. The oil temperature gauge never moved from its end stop which suggested that either the oil cooler was remarkably efficient or the gauge was faulty. The calibration, however, is from 60 to 140 deg. C. which rather explains matters. At tick-over, the engine sounds a little lumpy, but an occasional blip of the throttle eliminates the chances of a complete cut-out except when just started from cold.
On the test track, sustained cruising speeds in the nineties were possible and we were able to record a maximum of 109 m.p.h. At these high speeds the Supertone 85 exhaust system is surprisingly quiet, although the note is crisp and pleasant, giving the lie to the notion that there’s no power without noise. There is, however, a whistle at 80 plus, the price, although a small one, of tuning a production car without altering the aerodynamics.
Suspension-wise, the car remains relatively standard, the only addition being a Speedwell stabiliser bar fitted at the rear. The result was a ride no harder, nor softer, than a basic Mini, but heel-over was appreciably less and the car felt a wee bit more predictable to a rear-wheel-drive merchant, as I am, than the normal Mini. Outwardly the car appears as a meek lamb, its only distinction being the Speedwell badges front and rear, but beneath its bonnet lies a veritable wolf which, when unleashed, brought reactions from other drivers which never failed to keep me amused. Some were annoyed, others incredulous. The enlightened few were obviously impressed and jockeyed for a position close enough to see what it was that made the little Mini perform so spiritedly. The drivers of be-stickered, gimmick-ridden monstrosities–there are still plenty of them about—displayed reactions varying from bared-teeth anger to downright despondency. But I’d better stop before you begin to think that the Speedwell 1300 TC is a car designed solely to incite highway duels. Such is not the case; it is a combination of small car comfort (though I would personally invest in seats other than the uncomfortable standard ones which were fitted to the test car, sports-car performance, ease of cruising at high speed and a high degree of economy. (Continued)