Sports car projects : ADO21
MGF 20 years early
The ADO21 came about following the formation of BLMC in 1968. The reasoning was clear: the EX234 had been consigned to history, and the MG range was rapidly ageing. Of course, there was also the small matter of where MG would fit in the new empire given that Triumph was now a part of that same corporation, and offered a range of competing models… the Abingdon can not have gained much in the way of solace from the fact that the managers and executives that were being fastracked within BLMC appeared to be mainly Triumph men.
These concerns aside, the engineers at Abingdon were keen to move on from the EX234 and develop a sports car to replace the MG Midget (and Triumph Spitfire); one that would embrace modern trends and appeal to a wide and enthusiastic market. So, in mid-1969, Abingdon began work on a car that would eventually result in the ADO21. The idea that the new sports car would be mid-engined fell into that brief, as it was a layout that the Italians had embraced, and it was only a matter of time before all sports cars would be built this way. It was the logical assumption to make back in the late-1960s, anyway.
Very quickly, the mechanical package was defined: an E-Series engine/transmission package would be mounted amidships, and the suspension system would be a semi-independent layout employing Hydrolastic displacers; something which had also been used in the ill-fated EX234. According to David knowles’ book, “MG: The Untold Story”, the rear suspension was particularly sophisticated: it was a, “De Dion suspension arrangement, a sophisticated semi-independent system well-suited to mid- and rear-engined cars…” Under Roy Brocklehurst, the ADO21 took shape at Abingdon, and although there were some packaging problems inherent with the tall E-Series engine, the project moved along quite quickly.
Using the E-Series engine in the ADO21 meant that the “entry level” version would be a 1500cc model, but with the potential to expand to the 2227cc E6 engine (with little modification) through the 1748cc version of the E4. It was not lost on anyone that these engine capacity options struck into the heart of the MGB’s market sector – and therefore, the ADO21 was moving away from its original brief as the corporation’s smallest sports car.
The E4 Maxi engine’s height meant that the rear deck lid was on the high side, leading to a narrow rear window, flanked by a pair of flying butresses. Looking at the styling sketches and subsequent clay model, the height of the rear deck was cunningly disguised, and the clean lines at the front of the ADO21 were maintained at the rear.
Another problem was the transmission. Not so much the gearbox, but the change linkage; the 1968 Maxi used a three-cable arrangement, which resulted in the famously poor change action. In the ADO21, this arrangement would also be used, but with even longer cables, necessitated by the mid-engined layout. One can only imagine what the change quality would have been like!
Like the Triumph Lynx/Bullet projects that were concurrently being worked on at Canley, the Abingdon/Cowley ADO21′s existence was well-known within the BLMC corridors of power. There was the pressing matter of how best to serve the needs of the corporation as a whole, and because the ADO21 had become a MGB replacement, it was emerging as a direct competitor with Triumph’s Bullet. By late 1970, the full-size ADO21 model had been prepared and decisions about its future needed to be made.
According to Knowles, the ADO21′s situation was somewhat bizaare: initially, there was a great deal of pressure to complete the ADO21 in the early days, but then that pressure, “simply evaporated”. In his book, he goes further:
“After nine months of concentrated effort on the project, Rod Lyne says that work on the ADO21 simply petered out: ‘I never got told it had definitely been canned: I was simply told to leave it on the side in order to get on with other urgent work.’ The sold prototype languished in a corner of the development shop, gathering dust, until Austin-Morris engineering director Charles Griffin – who had supported the venture in the first place – paid one of his occasional visits, about 12 months after work had stopped on the vehicle. ‘You might as well chop it up’, was his instruction, so the entire car was destroyed.”
It was about this time that Spen King and Mike Carver went to the USA in order to find out what it was that the Americans wanted in the company’s upcoming sports cars. Given that they were told that the Americans wanted simplicity and reliability, it is easy to see why management decided to favour the conventional Triumph Bullet over the more advanced ADO21. Given that, the ADO21 was doomed…
However, looking at the styling models, it is easy to see why BLMC management requested that the Triumph Bullet should be restyled by Harris Mann, and that car be injected with some of the ADO21′s dramatic style. The spirit of the ADO21 lived on – it can be said – in the MGF, which shared that car’s engine layout and fluid suspension. Yes, the ADO21 was that far ahead of its time!
Written with reference to MG: The Untold Story, by David Knowles and “MG, by McComb”