Open the bonnet of a functioning, unmodified classic Mini and you will find a marvel of British automotive design. The A-Series engine was originally the work of Austin, a stand-alone manufacturer at the time but later submerged in the company which eventually became known as MG Rover.
The A-Series had a remarkably long life. It was introduced at a time when sugar, butter and meat were still subject to post-War rationing, yet you could buy a new car fitted with one ten years after the invention of the World Wide Web.
There were many changes in that time, of course, and no component of the final engine could be swapped with its equivalent from the first, but the basic design remained very similar throughout.
Many people were responsible for it, but the most famous was perhaps Harry Weslake, who designed the cylinder head. Among many other projects, Weslake was also closely involved with Jaguar’s early XK and V12 engines, and responsible for the Formula 1 unit which won the 1967 Belgian Grand Prix in the back of Dan Gurney’s Eagle. The little A-Series, designed more for economy than for performance, bore no resemblance to any of them, but Weslake was one of those engineers who could happily work on dramatically different projects.
As we’ll see, the Mini was by no means the only model to use the A-Series engine. In fact, it appeared in millions of small British mass-market cars, along with a similarly impressive number of kitcars and home-built specials.
The first car fitted with an A-Series engine was the 1952 Austin A30, which was intended (ironically, as you’re about to find out) to be a rival to the slightly older Morris Minor.
The A-Series was at this time as small as it would ever be, with a capacity of just 803cc. It was enlarged to 948cc for use in the A35 (pictured), which was otherwise almost exactly the same car with a larger rear window and a few other changes.
The Minor was launched in 1948 with an engine of a much older design than the A-Series. It was thoroughly revised in 1952, the same year that former rivals Austin and Morris were merged into the British Motor Corporation.
Not coincidentally, the Series II Minor used many Austin components when its predecessor had used none, with the obvious aim of reducing BMC’s production costs. One of them was the A-Series engine, which was available in 803cc and later 948cc form as it had been in the A30 and A35.
For the last nine years of Minor production, which came to an end in 1971, the A-Series was enlarged still further to 1,098cc.
In 948cc form, the A-Series was first used in a sports car in 1958, with an appropriate though modest increase in power output.
This was the first-generation Austin-Healey Sprite, nicknamed Frogeye (or Bugeye in the US) because of the unusual front-end appearance created by its protruding headlights.
It was in production for only three years, but is still popular among classic car enthusiasts even though later Sprites were, arguably at least, much more attractive.
There had been Austin A40s before, but what we’re interested in here is the one generally known as the Farina (because its shape was created by Italian design studio Pinifarina).
This was the replacement for the A35, and like that car was fitted only with the A-Series engine – the 948 until 1962 and the 1,098 from then on.
A40 Farinas were also built by BMC’s Australian arm and, under licence, by Italian company Innocenti.
The car which would later be named second most influential of the 20th century after the Model T Ford first appeared in 1959. It was designed by Alec Issigonis, who had also been responsible for the Morris Minor, and was radical in many ways.
At first sight, these did not include the engine. All production Minis used the A-Series, initially in a new size of 848cc, though much larger versions would be used over the car’s long career.
But it wasn’t quite as simple as that. While all the cars previously mentioned had the A-Series mounted front-to-back and driving the rear wheels, in the Mini it was mounted side-to-side and drove the fronts.
Furthermore, the gearbox, usually attached to the back of the engine, was now located in the sump and used the same oil. This compact arrangement meant that the engine and gearbox could be fitted in a relatively narrow space.
Two years after the Mini was introduced, BMC launched two versions with greater levels of equipment, chrome grilles and long boots providing extra luggage space.
Otherwise identical to the car on which they were based, the Riley Elf (pictured) and Wolseley Hornet were naturally fitted with the A-Series engine. They were reasonably popular for a while, but both were discontinued in 1969, more than 30 years before the Mini’s long production life finally came to an end.
The Frogeye Sprite was replaced in 1961 by a much prettier version whose basic design continued through two more generations.
The second, third and fourth Sprites were almost identical to the first, second and third MG Midgets of the same era (though nothing like earlier MGs which had been given the same name). Enthusiasts referred to all six collectively as Spridgets, and often still do today.
Like the Frogeye, Spridgets used the A-Series engine in first 948cc, later 1,098cc and eventually 1,275cc forms, the last being the largest capacity ever used for a standard production model. Competition versions could be as large as 1.5 litres.
The fourth Midget had no Sprite equivalent, since the Austin-Healey name had been abandoned by the time it appeared in 1974. It is also outwith the scope of this article because it used a 1,493cc Triumph engine.
The rarest A-Series
Cooper became the first team to win the F1 World Championship with a rear-engined car in 1959, and repeated the achievement the following year. In 1961, it was asked to develop high-powered versions of the very much front-engined Mini.
Most Mini Coopers had A-Series engines of 997, 998, 1,071 or 1,275cc, but a very small number also had a high-revving 970cc unit which allowed the car to compete internationally in up to 1,000cc classes.
Road-going 970cc Minis are now very rare and correspondingly valuable.
ADO16 was BMC’s code name for a wide range of mechanically identical cars marketed under the Austin, MG, Morris, Riley, Vanden Plas and Wolseley brands with model names of either 1100 or 1300.
The numbers referred to the approximate sizes of their A-Series engines, which were in fact 1,098 and 1,275cc respectively.
The ADO16 is perhaps best known now for having been given “a damned good thrashing” by John Cleese in an episode of Fawlty Towers, but in its day it was hugely successful. It is the only non-Ford to have been named as the most-registered car in a single year by the Society of Motor Manufacturers and Traders since records began.
Originally designed as a military vehicle, the Moke ended up finding success as a fun car, especially in warm countries where its lack of weather protection didn’t matter too much.
Mokes were built at first in the UK, later in Australia and finally in Portugal, where production ended in 1993, 29 years after it had started. All versions had A-Series engines, though in a variety of sizes.
Monte Carlo success and controversy
Although the A-Series had not been designed with high performance in mind, cars fitted with modified versions did tremendously well in motorsport.
The outstanding case of this was the Mini, which won an enormous number of races and rallies in the 1960s. Famously, it won the Monte Carlo Rally in 1964, 1965 and 1967.
Minis driven by the exceptionally talented Timo Makinen, Rauno Aaltonen and Paddy Hopkirk appeared to have locked out the podium in 1966, but their cars, along with Roger Clark’s fourth-placed Ford Cortina and Rosemary Smith’s sixth-placed Hillman Imp, were all disqualified for having non-standard headlight bulbs. Victory went to Citroen driver Pauli Toivonen, who had originally been classified fifth and, to his credit, seems to have been rather embarrassed about the whole thing.
The disqualifications caused an uproar which may actually have given the Mini more publicity than it would have done simply by winning the event.
The Allegro, or Innocenti Regent in the case of versions briefly built and sold in Italy, was not the most successful car produced by British Leyland, as BMC had now become.
It was criticised for its dumpy shape (which was not at all what designer Harris Mann had originally intended), its lack of tailgate and its ‘quartic’ steering wheel, even though this item was abandoned very quickly.
Less powerful Allegros used 998, 1,098 and 1,275cc A-Series engines. Others were fitted with the 1,498 and 1,748cc versions of the E-Series, which was partly responsible for the diversion from Harris Mann’s idea.
The E-Series was very tall, which meant the bonnet line had to be raised and everything else shifted around to suit. If BL had stuck with the A-Series, the Allegro would almost certainly have been a much more attractive car than it was.
A-Plus and the Metro
The Metro was intended to be a replacement for the Mini, though as things turned out it went out of production two years before the Mini did.
From the car’s launch in 1980, all Metros had an A-Series of either 998 or 1,275cc, or so it seemed. In fact, British Leyland had spent several years trying to come up with a replacement for what was becoming quite an old engine.
Radical solutions were attempted and then abandoned. Instead, the company spent £30 million revising the A-Series, and called the result the A-Plus. Everything had changed except the basic design, which was now being seen as old-fashioned.
The A-Plus was also fitted to the existing Mini and Allegro models. When what had originally been marketed as the Austin Metro became the Rover Metro in 1990, the engine was replaced by the much more modern K-Series, which remained in use after the Metro name was dropped and the car became known as the Rover 100.
A turbocharged version of the 1,275cc A-Plus was used for the MG Metro Turbo, the hot hatch of the range.
Race versions were quoted as producing around 200bhp, a remarkable figure for a 1.3-litre engine of the 1980s and more than double the output of the standard car.
Maestro and Montego
The Maestro (pictured) and Montego, launched in 1982 and 1984 respectively, were both large enough to need engines of more than 1.3 litres across most of their ranges.
However, the 1,275cc A-Plus was offered in both, for people who didn’t want to spend much money or go anywhere terribly quickly.
By the late 1990s, almost all the cars you’ve read about so far had gone. The sole exception was the Mini, which remained popular as a novelty vehicle even though it was no longer a serious rival to much more modern small hatchbacks and city cars.
The Mini was finally dropped in October 2000, 41 years after its own launch and 48 after that of the A30 and the engine which both cars, and so many others, had shared over nearly half a century.
Manufacturers of kitcars and complete vehicles, as well as home builders, were understandably keen to use the widely-available A-Series for their own purposes.
It would take far too long to list them all, but examples include the Mini Marcos, the Midas, the Cox GTM, the Fisher Spyder, the Metron, the Mini Cord (a Venezuelan Mini replica with a fibreglass body), some Davrians, the Terrapin, the Peel Viking, the Ogle SX1000, the Hustler, the Unipower and one of the best-named cars ever built, the Deep Sanderson (pictured).