MG 1100 Sport Sedan

The ADO-16

The MG Sports Sedan was loaded with features – and it needed to be, given the marques badge was adorning what was very obviously an Austin/Morris. Of course the Morris 1100 sported plenty of engineering innovation - making it one of the most advanced and practical cars then on the road. Although styled by Pininfarina, it did look pretty much like a box on four wheels, but the true beauty of the MG 1100 Sports Sedan was found in its high degree of functionalism.

The engineering concept of the Sports Sedan (more room in less space, made possible by the transverse-mounted engine) belonged to Alec Issigonis, then technical director of the British Motor Corporation. The pioneer of this concept was the BMC ADO-15, a design that first went to market in 1959 under the Austin and Morris banners and famous the world over as the Mini. The MG Sports Sedan carried the works designation ADO-16, and was a further development of the ideas that proved so successful in the smaller ADO-15.

On the outside, the ADO-16 was a small car, standing on a wheelbase of 9332 inches, with an overall length of just over 144 inches. However, the complete utilization of available space, made possible by Issigonis' concept, made it a comparatively big car on the inside. Four full-sized adults had all the head, hip and leg room they needed for short-to medium-haul comfort. The unique transverse engine (with integral transmission and final drive gears and front-wheel-drive design) was developed for several important reasons – reasons that we take for granted today given the proliferation of front-wheel-drive cars – but for the early 1960s it represented a major technological breakthrough.

Decades earlier car designers came up with the idea of rear engine design, which like the FWD configuration, did away with the transmission tunnel – but this was never as effective and usually had adverse effect on a cars handling, with only a few exceptions to the rule, such as Porsche. Designers had realised that a rear engine could not provide much luggage space behind the rear seat unless passenger leg room was decreased or the length of the vehicle was increased. Luggage space ahead of the toe board was limited by wheel arch demands to accommodate the wheels on full lock. Another consideration was that, with the weight of the engine/ drive package at the front, the vehicle always had inherently good directional stability. And yes – except for the likes of Porsche.

Sound Engineering

The power-plant of the ADO-16 was the well proven BMC "A" type, and except for the transmission and final drive gears located in the sump and increased bore and stroke, was identical to the thousands of "A" engines that were already doing duty in various BMC automobiles. It displaced a scant 67 cubic inches, and with two semi-downdraft SU carbs and 8.5-to-1 compression ratio, was rated at 55 hp at 5500 rpm, with 61 pounds-feet of torque at 2500 rpm. Coupled with a curb weight of 1900 pounds, the 1100cc screamer did a good job of pulling the MG Sports Sedan through both traffic and windy country roads. The acceleration times were comparable to many larger cars and faster than several other cars in its class. When accelerating the engine wound easily wind out to 6000 rpm. The action of the gearbox was smooth, with a minimum of noise. A hydraulically operated clutch required light pedal pressure and was very precise in operation. Third gear could be a bit hard to find at times and it was disappointing that, on the first iterations (and considering this model wore the MG badge), first gear did not come with synchro.

Hydrolastic Suspension

But despite the few quibbles, the MG Sport Sedan was a pretty good car to drive, and with fuel economy approaching 24 mpg it was also an economical one. The 10-gallon tank gave an operating range of around 300 miles on the highway. Lockheed disc brakes were standard at the front and the back wheels had eight-inch drums. Stopping power was excellent, with repeated, straight-line stops possible from any speed. Nose dive on hard stops was minimal because of the suspension system – a system that was an exclusive BMC development and was completely different from anything then (and now) in use. In saying that, we are including both the Mercedes and Citroen air and air/oil systems from years past. Compared to these two, the BMC system was the epitome of simplicity. It worked beautifully - there were no springs or shock absorbers as such, and no mechanical moving parts in the Hydrolastic suspension units.

Springing action was by rubber "springs"' located in each unit. A working fluid (water and anti-freeze) contained under pressure provided damping action and also applied a load to the rubber "springs," which in effect had a variable rate (as the loads increased so did their resistance). Front and rear Hydrolastic units on each side were interconnected by tubing. If a front wheel hit a bump, a load was applied to the rear wheel so that it anticipated the coming bump. This effect, plus the addition of anti-pitch bars at the rear, effectively eliminated any pitching motion that might be set up in the car when taking a sudden dip at speed. An anti-roll bar was used at the rear for added roll stiffness to balance out the high degree of roll stiffness that was inherent in the front suspension. The result was a suspension system that provided a smooth, jolt-free boulevard ride and at the same time had handling characteristics approaching those usually found on race cars.

On the Road

The Hydrolastic suspension ensured that the ADO-16 cornered very flat. As long as power was held on the front wheels, the car would understeer slightly in all types of corners. If the driver backed off suddenly in a corner, the car immediately showed slight over-steer. Neither of these conditions was excessive, and the car could be cornered well and fast by almost anyone. On the road, where the Sports Sedan's top speed of 80 to 85 mph allowed it to stay with or ahead of traffic, it showed good directional stability and was little affected by crosswinds. At high speeds, very little road shock reached the driver. Noise level from wind and engine is about normal for a car of this size. At 60 mph and above, the engine was really buzzing (due to the small-diameter tires and 4.13-to-l final drive ratio), but it's smooth — and even at 5500 rpm in top it doesn't sound as if it's straining.

The MG Sport had so much performance that the original standard fitment Dunlop tyres were found wanting - but at 80 mph these small 5.50 x 12 tyres would have been turning up an abnormal amount of rpm, which means distortion and excessive heat build-up. There are only a handful of reports of problems with the tyres – and under normal driving conditions we assume all went well – however if you know of particular problems we would love to hear from you. The exterior workmanship on the MG was comparable with other cars in the class, but the interior detailing left a lot to be desired. The carpeting in particular was reported as being shoddy by many motoring journals from the era – while the upholstery on the door panels was also well below par, with traces of glue residue evident on many examples.

The seats were contoured slightly for good support, and they remained comfortable even after extended use. In addition to the surprising amount of luggage room in the boot, extra storage space was provided by a wide shelf behind the rear seat and by panniers in the doors and flanking each side of the rear seat. Instrumentation was by a ribbon speedometer (with separate trip mileage odometer), a fuel and temp gauge, plus an array of multi-coloured warning lights.

The MG 1100 Sports Mark II

At the end of May 1967, BMC announced the fitting of a larger 1275cc engine to the MG, Riley Kestrel, Vanden Plas and Wolseley variants. The new car combined the 1275cc engine block already familiar to drivers of newer Mini Cooper and Austin-Healey Sprite models with the 1100 transmission, its gear ratios remaining unchanged for the larger engine, but the final-drive being significantly more highly geared. The Mark II versions of the Austin and Morris models were announced, with the larger engine making it into these two makes' UK market ranges in October 1967 (as the Austin 1300 and Morris 1300). An 1100 version of the Mark II continued alongside the larger-engined models.

Unusually for cars at this end of the market, domestic market waiting lists of several months accumulated for the 1300-engined cars during the closing months of 1967 and well into 1968. The manufacturers explained that following the devaluation of the British Pound in the Fall / Autumn of 1967 they were working flat out to satisfy export market demand, but impatient British would-be customers could be reassured that export sales of the 1300s were "going very well". MG, Wolseley, Riley and Vanden Plas variants with the 1300 engines were already available on the home market in very limited quantities, and Austin and Morris versions would begin to be "available here in small quantities in March 1968".

On the outside, a slightly wider front grille, extending a little beneath the headlights, and with a fussier detailing, differentiated Austin / Morris Mark IIs from their Mark I predecessors, along with a slightly smoother tail light fitting which also found its way onto the FX4 London taxi of the time. Austin and Morris grilles were now identical. The 1100 had been introduced with synchromesh on the top three ratios: all synchromesh manual gearboxes were introduced with the 1275cc models at the end of 1967 and found their way into 1098cc cars a few months later. Mark II versions of the MG, Riley, Vanden Plas and Wolseley were introduced in October 1968, at which time Riley abandoned the Kestrel name. The Riley 1300 Mark II was cancelled in July 1969, this unfortunately being the very last Riley.

Given the popularity of the 1300 the writing was on the wall for the 1100 models, and productin of the MG 1100 would end in 1968 - while the MG 1300 would remain in production until 1973.