Sports car projects : MG EX234

The MG EX234 project was developed in 1964 as a proposed replacement for the MGB. Under the skin lurked some very interesting engineering solutions…

 The Pininfarina styled EX234 was particularly pretty from this view.
The Pininfarina-styled EX234 was particularly pretty from this view

The EX234 project was instigated in early 1964 when the Abingdon engineering team’s thoughts turned to the issue of revising the MGB in order to give it a degree of chassis civility. The story behind the car was simple really; there was a palpable level of disappointment with the MGB, not so much for its styling or performance, but with the suspension system.

The trouble was that the ‘B was designed around an independently sprung rear end but, due to time and cost factors, this arrangement could not be implemented. This meant that the familiar MGB live rear axle arrangement was employed. Effective it might have been, sophisticated, it was not, and many MG testers felt that the ‘B’s road manners had suffered accordingly.

Given that BMC’s product range was moving – wholescale – towards Hydrolastic, it was a logical conclusion that any independently sprung MG sports car would need to use this layout, in order to achieve economies of scale. The decision was made, therefore, to go down this route – and using the Austin Gipsy’s final drive layout along with the now-familiar Hydrolastic layout of the ADO16.

It was around this time that the decision was taken to drop the idea of updating the MGB’s suspension, but employ the layout in a new body. Now that EX234 could be considered an entirely new car, the next step was to expand the project’s remit and, if a range of engines could be offered (i.e., the A-Series as well as the B-Series), it could also be pressed into service as a Midget replacement, as well as a ‘B replacement.

Lotus Elan or Pininfarina MG? Either way, this deliciously proportioned convertible continued the family style defined by the Midget and the MGB
Lotus Elan or Pininfarina MG? Either way, this deliciously proportioned convertible continued the family style defined by the Midget and the MGB

Pininfarina was duly tasked with producing new bodywork and, with its characteristic efficiency, they put together a tidy looking car within a few short months. As can be seen from the accompanying photographs, the final Pininfarina EX234 was somewhat more compact looking than the MGB, and that was no doubt a decision taken purposefully in order to bridge the gap between the Midget and its larger brother.

The EX234 that came back from Italy was A-Series powered and, according to David Knowles’ book, MG The Untold Story, there was never any serious work undertaken on a 1.8-litre version of the car.

Still, the A-Series-powered, Hydrolastic-suspended sports car had a great deal of potential and, when finished, it acquitted itself very well with everyone who drove the car. Knowles’ book relates this: ‘Roy Brocklehurst took the EX234 prototype to Silverstone where, according to Jim Stimson, it was driven by a few trusted experts… including John Surtees. Roy said that they told him that they thought the roadholding was as good as any car they had driven.’

Certainly that indicates – yet again – the fundamental excellence of Alex Moulton’s Hydrolastic system.

In the end, the EX234 became a victim of other – more pressing – priorities within the company. The MGB and Midget were still selling well, especially in the USA, and as a result the development of the EX234 was put on the back-burner. By the time of the BMC-Leyland merger in 1968, the EX234 had pretty much gone the way of the dodo – which is a real shame, given its dynamic excellence. However, the concept of the Hydrolastic MG did not die, as the existence of the ADO21, which came along a few years later, demonstrates.

It was sold at the Bonhams auction at Goodwood on 24 June 2016 for £63,100, including premium.

Here’s what Bonhams said about the EX234 in advance of the sale

The unique car offered here is one of the many fascinating ‘might have beens’ in the history of the MG marque. Its planning began in 1964 when Abingdon’s engineers’ thoughts turned to a ‘next generation’ MGB that would have better chassis dynamics: specifically, the new car would incorporate the independent rear suspension intended for the original but abandoned as too expensive. Designer Syd Enever’s team was responsible for constructing the prototype, code named ‘EX234’, raiding the BMC parts bin for the 1,275cc A-Series engine and gearbox, Austin Champ rear axle, and Hydrolastic suspension units. Suspension was by upper and lower wishbones all round, steering was by rack and pinion, and there were disc brakes on all four wheels.

Once completed, the rolling chassis was despatched to Pininfarina in Italy for bodying, and the result contains hints of the master coachbuilder’s FIAT 124 Sport Spider and Alfa Romeo Duetto, while at the same time incorporating the sawn-off ‘Kamm’ tail that would later appear on the Alfa Romeo 1750. EX234 was intended to replace both the Midget and the MGB, and despite being more compact than the latter offered a more generously sized interior. The exterior trim on either side was different: one style being for the GT version, the other for the open roadster.

Back in the UK, EX234 was enthusiastically received by all who drove it. In his book ‘MG – The Untold Story’, David Knowles has this to say on the subject: ‘Roy Brocklehurst took the EX234 prototype to Silverstone where, according to Jim Stimson, it was driven by a few trusted experts… including John Surtees. Roy said they told him that the roadholding was as good as any car they had driven.’

So why didn’t EX234 make it into production? At the time of its inception both the Midget and the MGB were still selling well, and it was felt by senior management that there was no pressing need for a replacement. The project was shelved. Following BMC’s merger with Leyland to form British-Leyland, the balance of power shifted within the reconstituted group in favour of Triumph, at least as far as thoughts of a new sports car were concerned, and when the time came it was the Triumph TR7 that was chosen, despite the MG marque’s greater popularity in the USA, B-L’s most important export market.

In 1977, with only 100 miles on the odometer, EX234 was acquired by the long established MG dealer Syd Beer, becoming part of his MG Museum collection in Houghton, Cambridgeshire. While there it was driven by motoring journalist John Sprinzel, who had been a works MG driver back in the 1950s. In the resulting magazine article (copy on file) he observes that the Hydrolastic suspension ‘kept the car beautifully flat and smooth through the corners, with none of the usual lurch over uneven bits of the surface. There was also no rear-end steer, and I felt that even without any development input that the handling was far superior to the current Spridget.

‘The interior was vast, and for my six foot three inches of height, there was space for legs, knees, arms, and elbows. The small steering wheel was set amongst excellent instrumentation, and occupants were surrounded by interior trim far better than has been normal on Abingdon products, with comfortable seats and two compact extra back seats with better legroom than in the MGB GT. There was excellent visibility and really good braking…

‘All in all, I concluded my little road test by thinking this would have been a delightful successor to both the B and Midgets, with good looks, great performance, and probably the continued money-making record of many years of Abingdon sports cars.’

Offered for sale by the Beer Family Trust, this unique and historic MG prototype comes with a current MoT certificate, its original V5 registration document, and a copy of the original factory specification sheet. The car also comes with a factory hardtop, intended for use on the GT version, and has a folding convertible hood made of an attractive flocked material rather than the vinyl used for contemporary MGBs and Midgets.

MG EX234 (1) MG EX234 (2) MG EX234 (3) MG EX234 (4) MG EX234 (5) MG EX234 (6) MG EX234 (7) MG EX234 (8) MG EX234 (9)

Keith Adams


  1. That rear drive Hydrolastic platform would surely have provided a far sounder basis for the ADO Marina – The economies of scale would no doubt have resulted in this sophisticated solution being more cost effective than putting the 1940s engineered Minor suspension back into mass production.

    • Without realising it, you’re getting close to where ADO77 was heading. Sadly, because of the disaster that was SD1, the program was cancelled.

    • Initially the Hydrolastic suspension was incorporated along with 4 doors for the Coupe body shell design. The rear doors were taken directly from the Alegro. The front was extended 4 inches between the front door and front wheels and the grille top area was shortened to give a slanted front instead of the vertical final product

  2. I saw a gleaming MGB in black the other day, a convertible, and for the first time realised just how tiny they are, how come you could build a 4 seater with a perfectly adequate boot into a space half the height of a Focus with the roof up? More to the point why aren’t we doing it now? Even the MX5 is much bigger and wider.
    As to the prototype, the styling is ugly, not sure which is worse, the front end or the back which obviously nicked bits from the landrover parts bin.
    Why didn’t they re engineer the MGB chassis for Hydrolastic/hydrogas? I can’t imagine it would have been horribly difficult. More to the point now, why hasn’t someone found a way to convert the heritage bodys so you could have an option with the cart springs and an option with maybe the suspension off a terminally ill MGF/TF … That would surely be an interesting drive.

    • The problem is safety, the MGB might as well be made of paper for all the crash protection it offers compared to a modern car.

      To make a car safe you need to absorb the energy of the crash somewhere other than where the driver and passengers are sitting. So you make a strong passenger cell, and surround it with weaker crumple zones in less critical areas that are designed to fail in a crash.

      These crumple zone take up space, as do side impact bars in the door, and other equipment like airbags. You couldn’t design a car as basic as an MGB or Midget, and be able to sell it legally.

  3. EX234 to me looks quite “feminine”, less sporty and aggressive than the MGB and more reminiscent of the Fiat 124 Spider.

    • Would have to agree, it also seems like BMC were trying and failing to avoid having EX234 resemble the Triumph Spitfire when featuring shades of the mk4 and 1500 models would have benefited the MG as well as allowed it to effectively replace both the Spitfire and Midget.

      A pity EX234 was abandoned rather then revived and carried over the styling of the MG ADO21, in the same way the latter was carried over by Triumph to what eventually became the TR7/TR8.

  4. Would it have been better to develop EX234 to replace both the Midget and MGB or instead sit in between both via Downton-tuned 83-106 hp 1.5-1.6 E-Series engines, while the MGB is uprated to a 106-127 hp 2.0-litre B/O-Series engine?

    Since the A-Series EX234 would inevitably be slower then the Midget even in Cooper S tune, while the B-Series in 1.8 form would likely not be much faster compared to the MGB. Also a pity the MGB never featured fully-independent suspension from the outset.

  5. It looks quite pretty from the rear, but the front looks like an MGB which has been sat on. The problem sounds to me to have been that it fell between the B and the Spridget in size and thus met neither car’s requirements . Incidentally, Jemma’s remarks about the MGB being tiny are rather strange to me – the B has more legroom in it than any other car I can think of , and every time I get in mine I am suprised by how much more room there is than in my E types .

    I was also interested in the IRS suggestions . The tooling requirements would, I think, have been enormous and the results would not necessarily have been all that good when one considers the problems with the Spitfire’s rear suspension . The shame is that the parabolic springs which are now available for the B , and which give a dramatically better ride , were not fitted during the production run

  6. @ Christopher

    Put it next to even something focus, Accent, original Mondeo sized, and stand back. It must be 2ft lower and a foot narrower than even my accent, if it wasn’t for those side bars they fit on semi trailers nowadays you could change lanes by scooting underneath. Not in front of traffic police..
    I’m not sure what it is about the EX car that I really dislike but it’s definitely not an improvement on the B. Was there any reason why they didn’t keep using the MGA Twin Cam for the B, other than its habit of eating cams?
    Has anyone thought to do a engine swap compatibility list? Which engines use the same mounts, bell housings, clutch size etc? Metro turbo engine in a B could be interesting or in an MGA..

  7. Ah , well I agree that modern cars are fat and tall by comparison ! The way cars have grown is extraordinary – I was looking yesterday at an Astra parked next to me, and it would have been a large(ish) car by the standards of the 1950s/early 60s. The twin cam had been abandoned long before the demise of the A, when the mark II went to 1622cc . The B is quite heavy, and needs torque , ( so the A series even turbocharged would fall a bit short of requirements , and certainly wouldn’t pull the axle ratios and overdrive on the MGB ) which was the reason for the engine’s stretch to 1798cc from 1622 . Nowadays , people stretch them to beyond 2 litres

  8. @ Chris Storey… yes modern cars seem to grow with every new incarnation. The current Fiesta is about the same size as a MK1 Focus and the recent Astra’s are as big if not bigger than late 1960’s Victors. As for the Mondeo, it’s bigger than a Zodiac or MK1 Granada me thinks.

    • Granada

      Length 180 in
      Width 70.5 in

      Length 186 in
      Width 70.5 in

      Length 186.4 in
      Width 69.5 in


      Length 188.1 in (hatch, 190.7 for saloon)
      Width 74.3 in

      mk4 (current)
      Length 191.7 in
      Width 72.9 in

      • Part of the reason the current Mondeo is so big is because its a global design hung around the Fusion from the land of the obese. Over there its considered “compact”. Surely Ford should have thought about renaming this car and producing it in up market trims only as a budget alternative to the likes of the Audi A6, adding something like a stretched Focus to the range as a 21st century Cortina. Ford who pioneered the C/D class in the 1960’s with that car now have a chasm between the Focus and Mondeo as big as that between the Anglia and Zephyr.

  9. One of the very simple reasons that cars are bigger is the increased safety standards. My old MG Midget had doors 3″ thick. In a side impact your were a goner. Same with the MGB and any other early 1960s car.

    My current MX5 has side impact protection beams, airbags, crumple zones etc, not to mention ABS, catalytic converter, PAS etc. [And a decent heater]. It is also a darn sight more comfortable than an MGB.

    In any significant crash, I would rather be in my MX5 than an MGB. no contest.

    Length 3,886 mm (153.0 in)
    4,019 mm (158.2 in) rubber bumper version

    Width 1,524 mm (60.0 in)

    Height 1,219 mm (48.0 in)
    1,295 mm (51.0 in) rubber bumper version

    MX5 Mk1
    Length 3,950 mm (155.5 in)
    Width 1,675 mm (65.9 in)
    Height 1,230 mm (48.4 in)

    MX5 Mk3
    Length 4,000 mm (157.5in)
    Width 1,720 mm (67.7 in)
    Height 1,240 mm (48.8 in)

    Food for thought.

  10. To get back to the subject of EX234, this was one of the cars that MG hid in their boiler house during the Stokes era, in case he decreed that it should be scrapped. (A lot of things were hidden away from Stokes, ranging from prototypes to Lord Austin’s Office in preservation at Longbridge!) EX234 eventually went into Syd Beer’s MG collection, maybe it’s still there?

  11. @ Tony Evans, add in a hard, non collapsible steering column, protruding switches, no compulsory fitting of seatbelts until 1965 and brakes without servo assistance, and you stand a far greater chance of being killed or seriously injured in a mid sixties car than one from the 21st century. Yet it had to be said, most motorists survived the sixties with no mishaps and looking at that MG is far more interesting than yet another crossover from Ford. I’d deffo go back to the era of British made sports cars from MG and Triumph, but with modern driving abilities and safety.

  12. I’m not quite sure why you regard brakes without servo assistance as being a safety demerit. They produce far better feel, are just as powerful, albeit requiring more pedal pressure, and best of all are not vulnerable to failure of the servo unit , which if it occurs can take you rather by surprise. Also, I wonder how many people ever suffered any injury from switches ? They are not in front of either driver or passenger . By the same token , a previous reference to side impact bars seems to me to offer a completely illusory notion of safety – quite how a piece of thin mild steel can dissipate the very considerable energy possessed by a car intruding into the door is something which has always baffled me. It must, of course, make some difference , but the difference seems to me to be likely to be minimal ( and of course side impacts are historically the most lethal)

    • It would be instructive for you to search out and study the head impact regulations for both Europe and the USA. Switches are very much included in the head impact zones.

      The intrusion beams in modern car doors are not there to absorb side impact loads. They exist to transfer those loads into the body structure. In the case of front door beams, into the A and B posts. The structure absorbs the impact so that you don’t.

  13. Makes you wonder if BL couldn’t have save itself a fortune on the TR7/Lynx and its associated factory by simply upgrading the B with a coil-sprung live rear axle – which Mr Knowles tells us it was meant to have had before reverting to leaf springs at the eleventh hour – and then plumbing in the Triumph slant four. Maybe carry forward the MGC’s torsion bar front suspension too – it made fitment of the Rover V8 so much the easier.

  14. @JH Gillson

    Certainly a very possible thing to do as the MG owners Club cells a kit that does exactly that along with a limited slip diff, power steering and much improved development of the much improved front end from the RV8.

    One could have imagined the MGB being developed with O Series and T Series and of course the Rover V8.

    But none of this could and would have happened, because the future sports Car Brand for British Leyland was Triumph, in principal they were right, the MGB was tired and Triumph was the better regarded brand than MG in the US. The original Triumph plans for a Roadster, Coupe and 2+2 GTE with a 2 litre 4 and a 3 Litre V8 was bang on what was needed.

    The problem was that the resulting TR7 was badly styled, under developed and the badly built like so many of the British Leyland products of the 70s.

    • I’m sorry Graham but you can in no way say Triumph was better regarded in the US than MG! The MGB was old and out of date but US dealers cried out for an MG version of the TR7 (and most of all TR8) because the Triumph brand did not resonate with Americans the way the MG brand did. MG outsold Triumph hugely, even when the B was old and the TR7 was new. They needed a new car by 1970 really but it needed to be badged as an MG or both (with different panels) as the MG version would have massively outsold the Triumph one.

      If BL had been brave enough to triple Rover V8 production and get an MGB V8 roadster and origanal Range Rover into the states by 1971, then developed an MG version of the TR8 that looked different enough to be an MG, they might have made enough money to have survived… But the sports cars never got the Rover V8 in numbers because the Rover production engine numbers were limited and BL never addressed that issue as they were afraid the fuel crises would destroy any market for it. Hindsight is a wonderful thing. 🙂

      • There were MG versions of TR7/8 looked at. However, we simply didn’t have the money to tool them. The ADO77/TM2 would have included an MGB replacement, but the SD1 disaster meant that there simply wasn’t the money available for the program.

  15. The July edition of Classic & Sports Car magazine (On sale from the 2nd June) has a fully illustrated 6 page feature all about the MG EX234.Its well worth a read.

  16. Very nice design indeed extremely elegant compared to the TR7, another missed opportunity

  17. With what became the Triumph TR7 eventually moving upmarket as opposed to directly replacing the MGB, the latter of which was left to remain in production. How would the TR7 project have been affected had the MG EX234 entered production as a direct replacement for both the Midget and MGB?

    Powered by a range of engines from a 1.3 to 2.0, it is arguable MG EX234 would overlap with the Triumph TR7 since the former appears to have been conceived as a slightly smaller sportscar with more sophisticated suspension compared to the models it replaced (and that without Hydragas entering in the equation), which the TR7 was moved upmarket by product planners.

    OTOH it is not certain whether the MG EX234 would have been able to use the Rover V8 like the MGB it would have replaced, let alone anything larger than a 2-litre 4-cylinder.

  18. This MG vaguely reminds me of the Datsun 240Z from the front and sides.
    Indeed the Z really took on MG in America and had a loyal following over here, as it had a powerful 2.4 six that could reach 120mph( the MGB struggled past 100), looked excellent, and, of course, was very reliable, well equipped and competitively priced. It really was the car MG should have become in the seventies.

    • Indeed one magazine proclaimed the Z series with the headline “The Big Healy Lives!”, possibly reflecting on the MGC’s failure to replace the Austin Healy 3000.

      • The 240Z probably capitalised on the MGB topping out with a 1.8 four cylinder engine and was also aimed at the six cylinder Triumph sports cars. In America the 240 Z undercut the MGB GT by $ 200 and offered far more performance and equipment for the money.

    • In EX234’s case one would be surprised if an inline (B/O-Series or E6) 6-cylinder could have been made to fit into the car, though despite being sized between the Midget and MGB could still see the Rover V8 (and related V6) being possible to slot into EX234 given the V8 already slotted into the same space as the B-Series in the MGB.

  19. Nate – check the engine bay photograph with the A series installed! Look at the oil filler cap and tell me that a V8 would slot into the EX234. The reason the oil filler cap is where it is is due to the low bonnet line.

    As for talk of using E series, of either 4 or 6 cylinders, or the B/O series these engines were complete and utter dogs when it came to emissions so without expensive re-design and re-tooling there was no way they were ever going to get into the NA market. This was recognised by MG at Abingdon as I spied a PE124 engined MGB in the proto shop there. This was when they were working on the O series at Abingdon on their test beds.

    The O series, even with fuel injection, had a terrible combustion trait at idle which put the HC emissions through the roof. The problem was associated with the inlet port swirl and the spark plug position. Longbridge engine design had managed to invert the lean burn concept developed by Honda, whereby you ignite a rich mixture which surrounds the spark plug and burns out to a weak mixture area within the chamber. The O series managed to have the spark plug in the difficult to ignite lean area of the chamber whilst the fuel rich area of the chamber was at the cylinder walls! This was proven to the engine hierarchy by making a ‘bath tub’ chamber out of a 14mm thick steel plate, fitting a head gasket either side, fitting flat top pistons that gave a level of squish, and putting the O series head on the top of all this with a suitably longer cam belt. The result was a revelation – the engine idled smoothly down to 500 rpm, and idle HC was reduced by over 70%. This was the spur to developing the 4V TR7 O series engine, which was then taken over by Longbridge to become the M series. Mind you the M series was a disaster due to the number of castings and fasteners required, resulting in a weak head which had a tendency to ‘curl its toes up’ and leak oil from the transfer passages. The original 4V TR7 O was designed with just 2 castings and was to be built off line and then installed on an O bottom end by external head bolts which were accessible on the top of the engine.

    Meanwhile the E series became the R series and ended up as the R series – there was a twin cam 4V version of the R series which was developed, again due to the need to improve the combustion characteristics for the original engine, this was in a Rover 216 which was a really quick car to drive with a very smooth power delivery and bags of torque from low speed. The problem with the E was the valves were displaced pointing at the near cylinder walls due to the use of a single OHC in a long stroke engine. All this resulted in a combustion chamber (shaped like a letter M in cross section) with an extraordinarily long burn time and again resulted in diabolical emissions. Again the 4 V version drastically cut the emissions, increased power, refinement in NVH and fuel economy was also improved.

    There were people within the organisation that recognised the problems with the engines and there was the developed knowledge to correct those problems but a lot of the issues were ignored by those with reputations to protect. Sad really as things could have been so much better.

    • Lord Lucan – Have had time to look further into David Knowles book on the TR7 since the previous posts, the Slant-Four powered MGB was said to be very tight fit and otherwise unviable proposition.

      Otherwise largely agree with what you have said regarding the other 4-cylinder engine options for EX234 outside of the A-Series in their current form or the unlikelihood of it featuring the Rover V8 without significant modification and upscaling, the Jon Pressnell book on Austin-Healey does briefly mention a mooted 1.5 engine for EX234 though nothing specific as could refer to either the 1.5 E, 1.5 Triumph SC or the 1.5 B for all one knows (if not maybe utilize a 1.6 B like on the MGA-powered Austin-Healey Sprite-based Project MARS prototype).

      Focusing on the intention for EX234 being a replacement for both the Midget (plus Spitfire) and MGB, the option of the B/O-Series engines (ideally 1.6-2.0-litres) would have initially made some sense despite their limitations had EX234 reached production early on though agree something like a clean-sheet O-Series or early equivalent of the 4V TR7 O series (before it became the allegedly compromised M-Series) would have been more ideal at the top of the range for the NA market (if not a 1.6-1.7 version of the Triumph Slant-Four – were it able to be installed in a viable way).

      It is also my limited understanding that experimental engine that became the E-Series was an altogether more compact and sophisticated design that featured many elements which would later appear on the S-Series. Am particularly interested to know more about the stillborn Twin-Cam 4-valve development of the S-Series and how it compares to both the 1.6 K-Series that superseded it as well as the 1.6 Honda used in the R8 (& original HHR) that may or may not have been used as a possible benchmark.

      Of the view some form of EX234 either in its current form or with ADO21 / TR7 inspired styling (followed possibly by Hydragas in place of the initial Hydrolastic suspension) would have both slotted nicely beneath the TR7 (replacing the B, Spitfire and Midget) as well as potentially had a long production life, loosely similar to how the early 1978-1992 Mazda RX-7 platform would go on to form the basis of the first two generations of 1989-2005 Mazda MX-5.

  20. Sorry all, there is a typo above in the last but one para –

    ” E series became the R series and ended up as the R series – there was a twin cam 4V version of the R series which was developed”

    Should read:-
    ” E series became the R series and ended up as the S series – there was a twin cam 4V version of the S series which was developed”

  21. Styling wise perhaps the MG EX234 could have benefited from another Pininfarina theme, more along the lines of the 1968 Fiat Dino Ginevra concept (preceded by the less refined Fiat Dino Parigi concept) that appeared around the same time as the BMC Aerodinamica 1800 / 1000 and BMC Mini Sports concepts.

2 Trackbacks / Pingbacks

  1. The cars : MGB development history | AROnline: The UNOFFICIAL Austin-Rover Web Resource
  2. Motor Show Review 1971: Part 6 – Roadhog

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