Carole Nash Classic Insurance Specialists

The cars : Triumph Stag development history

Even before it fell out of production in 1977, the Triumph Stag was regarded to be a classic car – it had everything: looks, power, a soundtrack to die for, and a certain sector of the market all to itself…

Yet it died after a short production run, and drove many of its first owners to distraction. The Stag was BL’s nearly car – it nearly had the armoury to take over the world, had it not been for that fragile engine.

The nearly car

The cars : Triumph Stag development history

IT was early in 1964 when Giovanni Michelotti asked Triumph design chief, Harry Webster, whether it would be possible possible for the company to donate a used example of the recently-launched Triumph 2000. The reason for this request was simple – Michelotti wanted to produce a glamorous one-off motor show special and use it as a showcase for the emerging designer’s talents.

Given the relationship between the Michelotti and Triumph was rock solid by this time, Webster said that he would gladly hand over one of the company’s race support cars after it had finished with the car. There was a proviso, though: if Triumph liked the design, then it would have first refusal on putting it into production.

In June of that year, Triumph duly delivered its 2000 following the Le Mans 24-hour race – and now it was up to Michelotti exercise his creative talents.

Michelotti’s masterpiece of design

Triumph Stag

Michelotti’s original 1965 convertible based on a shortened Triumph 2000 floorpan would prove an irresistible proposition for Harry Webster.

The car Michelotti produced was based on a shortened version of the 2000’s floorpan. The main difference was that the convertible had several inches cut from the wheelbase in order to give the car more balanced proportions. The engine, gearbox and suspension were stock Triumph 2000 items – and had already seen plenty of action in their former life as a race support car.

The concept car’s frontal styling was certainly a departure from Michelotti’s then current lineup, but in time, the look would emerge to become the family ‘face’ of Triumph.

Needless to say, the handsome two-seater convertible easily won over Webster – and the project was taken over by Triumph for a full in-house development programme. Michelotti was never even given the opportunity to publicly show the car at the Turin Motor show, such was Triumph’s keenness to keep the stylish car to itself. Early in 1966, work on the car began at Triumph’s headquarters in Canley, under the project name, ‘Stag’.

The reason for the delay between Triumph grabbing the car and the development programme getting underway was because of Canley’s limited resources. Harry Webster put it in these terms: “It was the usual problem of priorities, and money to tool it. I’m afraid it had to wait – we were particularly preoccupied with cars like the 1300 and TR5 at the time, and of course with the development of new engines.”

Another view of the Michelotti prototype - and the two men that were responsible for getting it into production. Harry Webster (left) brought the design back to Coventry and worked hard on productionising it, while Spen King (right) ensured that the engine used in the Stag was in three-litre form, as he felt the car needed more power

Another view of the Michelotti prototype – and the two men that were responsible for getting it into production. Harry Webster (left) brought the design back to Coventry and worked hard on productionising it, while Spen King (right) ensured that the engine used in the Stag was in three-litre form, as he felt the car needed more power

Shored up by the success of the 2000, Webster eventually convinced upper management that project Stag would be the ideal vehicle on which to base an aggressive expansion of exports to the USA. He later recalled: “Triumph realised back then that we couldn’t compete with the big boys – and we had to find a niche or market gap to fill, and that was where the Stag came in. It was aimed at the young executive, someone who’d gone through the motor bike/sports car/family and family saloon, and wanted something different, something sporty, but with creature comforts.”

Originally, the Stag was designed to use the two-litre straight-six engine in TS tune, but this plan was soon succeeded by one which involved the use of the 2.5-litre version of the straight-six. Several prototypes were built using this layout, but the company’s future engine plans were still somewhat in flux, and so, the Stag’s engine situation changed pretty regularly.

Engine indecision

Back in 1963, Lewis Dawtry, a distinguished member of the Triumph engineering team, drew up a report that laid out how he viewed the direction that Triumph’s engine range should go. In it, he stated that the engine family should consist of only two engines: one, a slant-four of 1500cc, which should provide the potential of enlargement to 2-litres – and the other, a small V8 that, essentially, was created by joining two of these engines together, sharing a common crankshaft.

It was around this programme that the Stag needed to fit. So, the initial development of the car was centred around the straight-six, to be used in the 2500, with future variations to be based on the upcoming V8.

Webster was also adamant that in order to succeed in the USA, the straight-six engine would need to be replaced by a V8 – the engine configuration of choice on the other side of the Atlantic. So, he used this as a bargaining tool to convince management to throw their weight behind the V8 programme. As it was, by 1966 Triumph’s V8 engine was already in its early stages of development, and it seemed the logical choice for the new car at the time. But in order to get the car onto the market within reasonable timescales, Triumph decided to introduce the car in 2.5-litre straight-six form, allowing for a careful development programme of the 2.5-litre V8, which could be phased in later.

Niggles in design

There were problems with the Stag development programme, but nothing significant enough to dissuade the company from forging ahead with it. Structural rigidity – or rather a lack of it – was causing concern for the Canley team, despite the later addition of double-skinned body panels. This led to the adoption of arguably the Stag’s most famous feature: the T-bar roll-over hoop. Harry Webster later recalled: “After ‘Micho’ finshed the prototype, we made some hand-built prototypes ourselves – and suffered from enormous scuttle-shake! Oh boy, it was horrid! You almost had to try and catch the steering wheel, if you know what I mean! The torsional stiffness of the body had gone to hell, of course, and the only way to get it back in was to join up the A and B-posts with a good torsional box across the top, and that’s exactly what the T-Bar does. It helped with the roll-over conditions, but it’s very much part of the structure!”

During the early months of 1967 and while the development of the Stag was in full flow, Triumph was joined by arch-rival Rover in the Leyland Motor Corporation. The reasoning behind this outwardly illogical purchase has been explained in the Whole story, but the net result was the two companies were now part of the same group – and competing models such as the Rover P6 and Triumph 2000 were now bedfellows. The ramifications of the takeover soon made themselves felt – and one main asset Rover brought to Leyland was its magnificent aluminium ex-Buick V8 engine.

By this time, however, development of Triumph’s own V8 was sufficiently advanced that Triumph felt it should continue to use it in the Stag – no matter how appealing this rationalisation may have seemed.

Following the formation of British Leyland in 1968, Harry Webster moved to Austin-Morris and in his place, came Spen King. King had been working intensively on the Rover P8 when he changed camps – and one of the immediate questions coming to Triumph, was that concerning the Stag’s engine. Because of King’s intervention – his feeling was that the 2.5-litre straight-six did not have enough power, and the new V8 under development should be the car’s sole power unit.

Triumph Stag

Even with the hood up, the Stag was a most handsome car. It summed up all that was good and bad about BLMC: wonderful styling, brilliant concept – one fundamental flaw.

Triumph Stag V8

Triumph’s new V8 was compact, efficient and reasonably powerful. The decision to use this engine in the Stag instead of Rover’s off the shelf V8 was an easy one for Triumph to make – development had been a lengthy and costly affair – and the last thing that the company wanted was to scrap it.

So, why no Rover V8?

The V8 had already been evolved from a 2.5- to three-litre unit by this time, and where it once used fuel injection, reliability issues forced the use of a carburettor set-up instead. Certainly it was a compact and light unit, but it was not without its fair share of problems. Without doubt, there was still a great deal of in-house rivalry between Rover and Triumph, and it is understandable that Triumph engineers would have been less than keen to use (what they perceived as) its rival’s engine in the forthcoming flagship.

King, however, was more pragmatic – and did raise questions.

King recalled: “I was told that they tried to put it in and you could not put it in and I believed them. I probably shouldn’t have believed it.” However, the decision was not just based upon the pride of Triumph, but also one of production capacity. He continued: “…there were big investments, which had been recently made in both companies for making V8 engines. There wasn’t the capacity for stuffing them in Stags as well. If you are organized to make something, you have got to have a go at the balance between capacity for making things and what they plan (probably dead wrongly because that’s what they normally get wrong more than anything else) is planned amount of sales of any given future motor car. As planned, as I remember it, there wouldn’t have been the spare capacity for V8 engines from the Rover Company to put into Stags. That was an extra thing that people forget about.”

British Leyland would pay a terrible price – because the car’s image suffered massively – for this decision.

As it was, King’s decision to delay the introduction of the Stag until the V8 was ready only added to Triumph’s problems – the car’s weight went up slightly, and because there was no longer a need to use the straight-six, extensive modifications were made to the engine bay. In the end, the Stag shared precious few internal components with the car it was originally closely based upon.

Caught in the BL trap

Wider corporate issues also beset the Stag’s development programme, and because of this, British Leyland would not stomach its launch being delayed any longer. Although many commentators have subsequently spoken of the ease in which a Rover V8 would fit into the engine bay, to do so as late as 1968 would have undoubtedly meant the launch date of the Stag would have slipped even further back.

As it was, Rover and Triumph’s model programmes were already being put under minute scrutiny – and that sense of rivalry was being fuelled by the fact that both Solihull and Canley knew there would need to be future rationalisation. And that would inevitably be to the cost of one or the other.

Triumph Stag

The Stag opened up new markets for British Leyland – the company was well served with both Triumph and MG sports cars, but the Stag was something else again: a grand tourer. Essentially, the Stag created a market niche and although it was phased out in 1977 after a production run of nearly 26,000, it is still viewed as the quintessential British “classic” sports car.

The Stag was launched in June 1970 and immediately created a favourable impression with buyers, who were quite literally enamoured by its simple beauty and its gorgeous engine note with accompanying exhaust ‘woofle’. Performance was good – its 2997cc engine certainly did everything asked of it and the 145bhp maximum power output compared favourably with the 143bhp from the 3528cc Rover unit. Sales started briskly and the effect on the Triumph range as a whole was marked – the uplift in image was there for all to see…

The honeymoon period didn’t last long though, and buyers soon found themselves falling out of love with the appealing new car.

Despite its grand ambitions for the Stag, Triumph was finding it difficult to get the quality right on – and the situation wasn’t helped by the dispersed nature of its production (bodies produced at Speke in Liverpool, and final assembly in Canley). Tales of build issues and reliability niggles soon started doing the rounds, and as quickly as BL put one thing right, it seemed another problem would emerge. However, if minor fit and finish problems irritated owners, they were nothing compared with the tales of woe that would emerge about the brand new engine.

Although Spen King told us there were few engine problems in development, this certainly proved not to be the case when it came to production versions. According to Stag specialists today, inherent problems were aplenty. The excessively long single-link timing chains suffered from poor tensioning – and to avoid expensive failures, they needed replacing every 25,000 miles – which would certainly seem to be a design fault. Manufacturing issues such as inadequately sized main bearings, cylinder head warpage due to poor castings, and water pump failures related to drive gear shearing could not be blamed on design weaknesses.

Whoever was to blame for these faults, the end result was a shattered reputation, and declining sales from the point stories of Stag engine failures became widespread…

A unique car…

When the Stag hit the market, there literally was no opposition for it. In contemporary advertising, Triumph highlighted the glamorous nature of the Stag, comparing it positively to Mercedes-Benz and Alfa Romeo’s products… Certainly the advertising department were correct to do so, as it was a very satisfying GT car to drive…

Given the laid-back and pleasantly long-legged nature of the Stag, it comes as no surprise that most owners opted for the Borg-Warner three-speed automatic transmission. Its smooth-shifting nature really suited the car – and did a far better job of cog-swapping than the manual ‘box, which was a derivative of the ancient Triumph TR2 gearbox. Thankfully, the Stag was offered with the option of overdrive, and that made for relaxed high speed cruising.

Once it became clear that BL was in a financial pickle, the Stag’s production development became a low-priority issue – and it is for this reason that it didn’t really change much during its seven-year production run. Two models were produced, the MkI (1970–3) and MkII (1973–7), but there are very few differences between the cars.

In the end, a mere 25,877 Stags were produced between 1970 and 1977. The Stag died simply because there was no money in BL’s kitty to put it right – and a car which used a unique engine, and which accounted for so few sales was a luxury a company fighting for survival could not afford. When it quietly slipped into obscurity, the Stag was mourned by few – but within the space of a few short years, it picked up a cult following, and remains today the doyen of classic British cars – and lines up alongside the MGB and Morris Minor as the most iconic classics of the time.

That might account for the Stag’s amazingly high survival rate.

We wonder how different things would have been had the Rover V8 been fitted at the earliest possibility… assuming BL workers could ever have been coaxed into building enough of the things…

Triumph Stag

Posted in: Stag

21 Comments on "The cars : Triumph Stag development history"

Trackback | Comments RSS Feed

  1. Howard says:

    Another BLMC/BL car to have nearly hit the bullseye:Maxi,SD1,Princess,Maestro,etc,etc.

  2. francis brett francis brett says:

    The midlands mercedes,this is simply a stunning car even with all its faults,i think it gorgeous and you can never mistake the noise of the stag 3 litre V8-music.

  3. Jamie says:

    The Stag never quite did it for me although I have to conceed it does have something going for it.
    The shocking quality issues hit a lot of the most expensive BL products in the 70s – like the modern day “halo” models; just in BLs case, in reverse – mainly due to a disaffected, striking workforce and money wasted instead of being used in a more targeted fashion.
    I’m not sure about the comparison to models like the Maxi, Princess and Maestro are justified. After all, those were never “right”, the Princess a case in point, the original design being far better than the end product, but also including slightly wobbly suspension. How that was supposed to compete with the Cortina or Cavalier etc I don’t know!

  4. Vaughan Evans says:

    This is an excellent account of the history of this car. I’ve always considered it to be the most beautiful car ever made.

  5. Timbo says:

    Probably one of the best designs to come from BL competeing with the likes of the Mercedes 350 and some other continental designs of that time.
    If you had a Stag in the 70s you were an individual and someone who had money or done well.
    In my opinion the best colours of the time were Saffron yellow or white with the PI rostyle wheel trims.
    In the early 80s you could pick up a decent un restored runner for £1000 that did the job aalthough it may have had looming engine problems which were a nightmare blown out of proportion by the motoring press for all time.
    One of the best cars i had a 1977 auto in Inca, those were the days.

  6. Paul says:

    @1 – Yes the Stag nearly hit the bulls eye. As for the Maxi, Maestro etc I think they ended up off the board bouncing off the wall! – The Stag was such an excellent concept with real potential that I wonder why BL didnt have another go, basing a car off a shortened SD1 platform, with of course the Rover V8 – Its the sort of thing a premium manufacturer would do without thinking these days. Minimum investment with the opportunity to charge a premium over the base product. Would also have filled up all the spare capacity at Solihull.

  7. Yorkiebusdriver says:

    There still seems to be an awful lot surviving too, but not sure how many will still be on Triumph v8 power

  8. Bob Wiles says:

    As an engineering student in the late 1970s, I spent my university holidays working for an engine re-conditioning firm which had gained a reputation for specialising in Stag engines. I witnessed some real horrors – failed attempts to literally hacksaw cylinder heads off because the angled steel head studs had corroded solid to the alloy heads; big holes in the sump coupled with a piston/con-rod count of seven due to timing chains slipping or breaking; broken water pumps because the impellor retaining screw was left hand threaded; failed head gaskets due to massive erosion of the alloy head around the waterways – the list goes on.
    Yet for all that I loved, and still love, the Stag. Nothing compares to that wuffly V8 note and smooth, relaxed driving style. I only wish I’d bought one when they were cheap…

  9. Dan says:

    A colleague has one that he and his brother have restored, complete with the ‘correct’ Triumph V8, brown velour interior and original wheels. It’s a daily driver through the summer, and he reckons it’s pretty reliable.
    They’ve fitted an upgraded alloy radiator, and installed an aftermarket expansion tank into the cooling system. With that, and religious coolant changes, he reckons it can sit for hours on the M25 in the middle of summer without any overheating problems.
    Beautiful car. Looks and sounds a million dollars, and always attracts an admiring crowd in the office car park.

  10. Chris Exley says:

    When I was 13/14 yrs old I’d dream of a stag. Just like the one on the 70’s series ‘Hazel’. Now at 54 I’ve finally got one, a white mark 1 with 4speed manual with overdrive. It’s great, and filled with history. British leyland did make some great cars and this is one of them. Thanks to all those Canley factory workers, god bless them all.

  11. Nate says:

    While understandable that Triumph didn’t want to use the Rover V8 to power the Stag, why didn’t they consider the 2.5 Coventry Climax CFA V8 engine that was originally intended for the stillborn baby XJ project?

    After all, the engine was installed on Leonard Pelham Lee’s personal Triumph 2000 Estate that going by Coventry in Climax by Walter Hassan produced more than 200 bhp at 7000rpm (engine weight only 300ib) in flexible sports-car tune.

  12. mike price-james says:

    Reliant Scimitar GTE & Triumph Stag Twin Road Test 1970

  13. Nate says:

    Read up on another site that the original idea behind the Triumph Slant-4 and V8 engines was to build a family of 4, 6, V8 and V12 cylinder engines with the 6 and V12 being killed off very early on in the concept phase (via the Code Name: Triumph Stag Michelotti’s Masterpiece DVD).

    What other Triumph sources mention the Triumph Slant-4 / V8 originally being part of a larger engine family?

    Would have been interesting to compare the Triumph Slant-6 with the Triumph I6 and later SD1 Six, assuming it was indeed a Slant-6.

    Also interested to know whether a Triumph V12 would have retained the same 90-degree V-angle as the Triumph V8 or instead feature the familiar 60-degree V-angle as found in other V12s by Ferrari, Lamborghini and Jaguar.

  14. Richard Davies says:

    Sounds interesting, I’ve not heard of those engines before.

    I was wondering if the 6 cylinder could have been a V6 as Ford & Chrysler Europe were developing engines of this layout at the same time, with & Renault, Peugeot & Volvo soon to follow with a joint effort.

    This could have also have lead to a 3 cylinder of around 1124cc, assuming the cylinders were the same size as the V8.

    IIRC 60 degree is best for a V6 & V12s & 90 degrees for V8s, though the PRV V6 seemed to cope with being 90 degrees.

  15. Andy Wood says:

    Shame about the penny pinching that went on to weaken the strengths of the original slant 4 which was the basis of the long living Saab engine and developed by them into the turbo and T16.

    Early 70’s, as a Technician Apprentice at Hepworth and Grandage (Hepolite & Powermax piston manufacturer)I worked on Product Development (engine test) for six months. Ran a Triumph 1700 c.c. slant 4 (proposed Saab engine) for a 500 hour endurance test, totally reliable and dead easy to work on. At the same time another team was running a Dolomite Sprint engine, actually produced more than the claimed b.h.p. This was as production engine and not a prototype although stripped, inspected, measured and rebuilt by the engineers before test as normal.

    Interesting other tales to tell including the time spent in the Drawing Office, hours spent looking at archive work on BMC/BL engines including the o.h.c. A series with variable valve timing. Designed the ring pack for the O series engine. Calculations in those days were using a new fangled electronic desk top calculator with a till roll print out resulting in yards of paper which had to be checked and submitted with the drawings for review and approval.

  16. Nate says:

    It might have been a 90 degree V6 instead of a Slant-6 though cannot be sure, know that Maserati and Buick also had 90 degree V6 engines.

    A 3-cylinder engine derived from the 1850 Dolomite Slant-4 (including 6v and 12v versions) was allegedly looked into during the 1970s (in Jeff Daniels book on BL) long after the 6 and V12 were killed off.

    • Kev says:

      We looked at packaging that engine into the ADO88 and LC8, along with the Daihatsu 3 cylinder 1.0L engine and the Norton twin-rotor Wankel unit. There were two of the later built as drivable cars, although I don’t know what happened to them.

      • Nate says:


        Interesting also read that the 6v/12v Triumph 3-cylinder engines were used in the Allegro at one point, was it down to costs that eliminated the Triumph unit (along with the Daihatsu and Norton engines) in favor of the A-Plus for ADO88 / LC8, a flaw in the design or the fact that the Triumph unit was simply not a great improvement over the A-Series?

        Speaking of ADO88 and LC8, was wondering if you could confirm that diesel powered variants by Daihatsu and VM Motori were looked into?

        Seem to recall an article by Car Magazine about BL looking into a 1.5 3-cylinder version of the 1.8 3-cylinder VM Motori diesel found in the Alfa Romeo 33 for use in what eventually became the Metro, though not sure how accurate the info is.

  17. Richard16378 says:

    Very interesting I was only lightly pondering over a 3 cylinder version but thought correctly.

  18. paul says:

    Fair enough that capacity concerns initially drove the engine decisions in the direction of the 3 litre Triumph unit. But by the mid 70s it was clear that this unit was a dog whilst SD1 volume was coming nowhere near wiping out Rover V8 production. A cheap fix would have been to drop the Rover unit into the Stag and give it a go in the phase 2 cars rather than simply throwing the towel in.

Have your say...