Database: Triumph Stag 1970-1977

Database: Triumph Stag 1970-1977

Database: Triumph Stag 1970-1977

One of BL’s ‘nearly’ cars, the Triumph Stag offered a taste of the exotic even the Germans struggled to match but was a victim of the corporation’s other problems. Words: Paul Wager.


The car which gained an unfortunate nickname back in the day but which is now one of our most-preserved classics.


It’s a paradox, the Triumph Stag. Its survival rate is one of the highest of all the ’60s and ’70s British classics, yet back in the day when they were still modern cars they gained a terrible reputation for mechanical fragility.

Which, with the benefit of hindsight, it appears was somewhat undeserved and perhaps a product of the independent garage trade of the era not really being geared up towards an all-alloy twin-cam V8.

Regardless of the car’s reputation as it aged, the Stag was well regarded as a new car and represents something of a high point for BMC/ BL. After all, when the Stag was launched in 1970 the only other maker which could offer you a four-seater V8-powered convertible was Mercedes – and that came with a pretty hefty price increase over the Triumph.

1976 Triumph Stag Auto

Ultimately the Stag stands as another chapter in the continued ‘what might have been’ saga of British Leyland, but also stands on its own as an effortlessly stylish and brisk grand tourer.


HISTORY

The story of the Stag begins in a rather unlikely place with a timeworn pre-production Triumph 2000 saloon. A pre-production car, 6105 KV had already seen a hard life as a race support vehicle for the Spitfires in the 1964 Le Mans race and when its duties were over, it was driven 1000km south to Michelotti’s studios in Turin.

The Italian stylist was by then Triumph’s go-to man when it needed a new model or a facelift and he had requested the chance to create a show car based on the Triumph 2000 saloon. The original intention had been to use it as a motor show display car to promote his studio and design capabilities.

This was to be very much a private venture by Michelotti rather than an official company venture and so he was left to get on with it, working away quietly until Triumph chief Harry Webster arrived at the studio one day in 1966 for a regular visit.

The accepted version of events is that Triumph had given Michelotti the donor car on the basis that if the company liked the result then it would have first refusal on productionising it and it appears that Webster was indeed very much taken with it. In his title ‘Triumph Cars – the complete story’ the late Graham Robson recalls Webster commenting “I instantly made my own decision on behalf of the company and Michelotti that I couldn’t let him use it in a show now that he had finished it, but that I wanted to keep it!”

Michelotti had created an elegant four-seater convertible from the big saloon, complete with a wheelbase shortened by six inches. With its clean lines, the early prototype has something of the look of the later Peugeot 504 convertible but this elegance would come to be a problem later on.

In what must have been a slight blow for Carrozzeria Michelotti – which presumably had nothing to display on its Geneva show stand that year – once the prototype arrived back in Coventry, it sat in storage for some time. As Webster later pointed out, the reason was a practical one: “It was the usual problem of priorities and money to tool it,” he admitted, pointing out that at the time the firm was busy with the front-drive 1300 and the TR5 as well as developing new engines.

As a smaller player in the business though, Triumph was well aware that it would be better served by exploring niches rather than competing head-on with the major European makers in volume segments and one niche they had identified was that of a mid-sized four-seater convertible. As conceived by Michelotti, the open-topped 2000 was perfect for this and so work began as soon as resources were available.

One problem which was identified early on was a significant lack of structural rigidity in the bodyshell with the roof removed. Double-skinned panels were added in an attempt to improve it but the eventual solution was the ‘T-bar’ which became a signature feature of the car.

This served to replace the strength lost by the roof without unduly affecting the car’s sleek lines but it also gave the project a degree of future-proofing: in the late ’60s it was widely felt that the National Highway Safety Traffic Administration in the USA would eventually pass legislation banning the sale of full convertibles. By retaining an inbuilt rollover protection structure the Triumph would sidestep such a ban if it ever became an issue – which in the end it never did.

By this time, precious little of the original saloon structure still remained. Triumph’s Engineering Director John Lloyd later admitted that the development team had originally hoped to get away with lightly modified Triumph 2000 tooling parts, but by the time all the required alterations had been made, the body development department pointed out that brand new tooling would be just as cheap.

Other problems with the prototype included Michelotti’s headlight treatment, which aped American styling trends by concealing the headlights when not in use. The lamp units were covered with slatted panels matching the front grille style which motored away when the lights were switched on, but when this later turned out to be easily jammed by ice and road dirt, the design was ditched.

While the Stag was still in development, it was recognised that the saloon model on which it was based would be due for a mid-life facelift to freshen its showroom appeal and of course Michelotti was called in for the work. Unsurprisingly, the result was essentially that of applying the front and rear treatment of the Stag prototype (without the covered headlights of course) to the saloon, with pleasing results and the longer tail giving a bigger boot.

While the bodyshell development was proceeding smoothly, the question of what would power the Stag was a much bigger issue. Clearly a car competing in this market would need more than four cylinders and the original plan had been to use the 2-litre straight-six engine. This was later changed to the 2.5-litre six, the idea being that the car would be launched in this form and a V8 added later.

The idea of a small V8 had been under consideration for some time since Triumph engineering veteran Lewis Dawtry had proposed back in 1963 that the firm’s engine range should be rationalised into just two designs: a 1.5-litre four and a V8 created by joining two of them together around a common crankshaft. As we know, that never happened but the 3-litre capacity of the V8 and many of its design features did recall the 1500cc four-pot engine. The V8 engine was already in development by 1966, but the likely potential of the new car in the US market gave it a boost, since it was agreed by everybody from Webster downwards that V8 power was a must for this market.


THE ROVER QUESTION

At this point a rather big spanner was thrown into the works with the creation of British Leyland which saw Rover and Triumph under common ownership.

Rover brought its own ex-Buick V8 engine to the party and no doubt there was consternation at Canley when the idea of replacing the Triumph V8 with the Rover unit was inevitably discussed.

Newly installed engineering boss Spen King recalls being told that the Rover engine simply wouldn’t fi t and although he later admitted he probably should have doubled-checked, he believed what he was told and the Triumph engine remained in development.

It was in many ways superior (on paper at least) to the Rover unit; similarly of all-alloy construction, it employed twin overhead camshafts and had originally been envisaged as running fuel injection while the Rover unit still used pushrods and carbs.

Shortly after the arrival of King it was decided that the original 2.5-litre V8 lacked low-speed torque and so the decision was taken to enlarge it to a 3-litre capacity. This brought with it a handy increase in output, at which point it was then felt that the rest of the drivetrain needed beefing up to suit. The result was that a stronger gearbox and rear axle were specified, alongside bigger brakes and larger 14-inch wheels.

The question of how close the Stag came to being fitted with the Rover engine is destined to remain a subject of speculation but the many cars which were retrofitted with the Rover unit in later life suggests that the prototype fitters were somewhat economical with the truth in their replies to Spen King.

One thing which is certain is that Rover itself was flat-out producing engines to meet its own demand and so would have been unlikely to have sufficient capacity to supply Triumph too. It would also have been recognised that a significant investment had already been ploughed into the Triumph unit which the new BL bosses would have been reluctant to write off without results.

The end result of the powerplant debate was that the six-cylinder car was dropped from the product plan and the Stag was launched with the 3-litre V8, which would feature twin carburettors instead of fuel injection, the company’s experience with the Lucas-injected 2000/2500 having frightened it (and buyers) away from this newfangled technology.

IN PRODUCTION

The Stag was launched in June 1970, with very few options: just the single 3-litre V8 engine and a choice of manual four-speed using a modified version of the old TR2 box, or the three-speed Borg-Warner 35 automatic. Overdrive was optional on the four-speeder until 1973, at which point it was made standard with the automatic a no-cost option. Very late production models received the Borg Warner 65 in place of the Model 35 unit.

The standard wheel was a steel rim with a Rostyle-like pressed cover, while the GKN alloys were an option, as were proper spoked wheels with knock-off hubs – although these were most commonly seen on US-market export cars. Electric windows and power steering were standard, with air conditioning optional and also uprated Koni dampers.

The bodyshells were produced at the Speke factory on Merseyside and were then painted and trimmed at a separate facility nearby, before being sent down to Coventry for final assembly, which is why it took a while for the first cars to reach customers.

This situation would persist for the entire lifespan of the Stag, which was destined to be just seven years – back then a dramatically short time for any new model.

This was due not so much to the reliability issues of the car in service but to the everworsening finances of British Leyland. A lowvolume V8-powered convertible was in many ways an irrelevance compared to the task of regaining ground in the volume saloon market and the Stag was sidelined to some extent, not aided by its growing reputation for mechanical fragility.

It received a facelift in 1973, the so-called Mk2 cars gaining a satin black treatment to the sills and rear panel as well as twin coachlines. Inside, the warning light arrangement was modified with the needles of the instruments pointing upwards and the interior lights moved from the B-posts to the T-bar.

Later examples of the Mk2 from 1974 reverted to body-coloured sills, although many were fitted with stainless covers which were surplus from US-spec cars. The Mk2 cars also received a high-pressure cooling system. The Stag production lines fell silent in 1977 after 25,939 examples had been produced with its best year being 1973 when 5446 were made. Sadly, its export potential was largely unfulfilled, with only 6780 being exported. Curiously, the situation is reversed today, with the Stag enjoying one of the highest survival rates of all the ’70s BL cars.

THE GREAT RELIABILITY ISSUE

It’s generally reckoned that this dispersed production arrangement contributed to the reputation for poor quality the car picked up in its early years, but in reality this is something of an urban myth. As new cars, the Stags were regarded by the press of the time as being no better or worse than the average new car of the time as far as fit and finish was concerned and indeed, most of the long-term magazine test reports have little to report in the way of failures.

It was when the cars left the dealer network that problems began to surface and these chiefly surrounded the engine. Being an alloy unit, it needed the anti-corrosion properties of proper anti-freeze rather than plain water, something which was often overlooked by mechanics of the time with disastrous results for engine cooling when the block furred up internally.

It’s generally regarded that the standard cooling system was adequate for an engine in perfect condition but had no capacity for neglect.

The original intention to use fuel injection had been one reason why the water pump ended up relatively high in the block – it left room for an injection pump to be driven from the auxiliary shaft – meaning that water level had to drop only slightly before the unit had nothing to pump.

The long single-row timing chain also required changing every 25,000 miles and if not attended to, had a tendency to stretch with valve/piston damage potentially happening even before the chain snapped.

Elsewhere, the design of the cylinder head bolts caused issues. A mixture of vertical and angled studs was used and the studs expanded and contracted at a different rate from the heads and block, allowing the heads to shuffle slightly relative to the block. This resulted in head gasket issues and a reputation for cooling problems.

With high quality castings and careful assembly, this wouldn’t have been an issue and indeed it’s reckoned that the pre-production engines, which used castings from an outside supplier, were problem-free. In production it was a different matter as the labour unrest within BL at the time meant that quality standards weren’t up to the care required to assemble the Stag engine.

In practice, the car didn’t gain its reputation for engine issues until it had been in production for a few years, by which time they were generally being maintained by back street garages unfamiliar with the engine’s unusual maintenance requirements.

Cam chain swaps were missed, anti-freeze was skimped and the result was that many cars were retrofitted with either the Rover V8 or the Ford Essex V6.

T-bar roof arrangement addressed concerns over future US regulations and also poor body rigidity from the cut-down 2000 saloon shell. Today the market values Stags still running the proper Triumph engine.

As a V8-engined four-seat convertible, the Stag was almost unique in the market. Hardtop made it a real year-round proposition.

Early prototypes used concealed lamps and lacked the T-bar. Twin-cam V8 was at the heart of the Stag’s appeal… and also its reputation for fragility.

Late Mk2s featured body coloured sills, although many were fitted with US-spec stainless covers.

Triumph V8 was technically more advanced than the Rover alternative. Interior was similar to the 2000/2500 saloon. Automatic option was a Borg Warner three-speed.

GKN alloys were an original option.

YOU DIDN’T KNOW...

REPLACING THE STAG

The grand plan had been to replace the Stag with a development of the TR7 line-up, which was originally destined to be so much more than the one model which made production. In addition to the two-seater coupe the line-up was originally slated to include a four-seater coupe under the name Lynx and a four-seater convertible badged as Broadside which with the V8 engine (Rover, rather than Triumph) would have picked up where the Stag left off.

Sadly, when industrial strife caused BL chief Michael Edwardes to move TR7 production from Speke to Canley and then to Solihull before axeing the model entirely, it wasn’t to be. The sole Broadside prototype survives in the Collections Centre at the British Motor Museum as a reminder of what might have been.

SPECIFICATIONS

  • ENGINE 2997cc V8
  • MAX POWER (BHP/RPM) 145/5500
  • GEARBOX Four-speed o/d or three-speed auto
  • ECONOMY 20 mpg
  • LENGTH 4.41 m
  • WIDTH 1.61 m
  • WEIGHT 1197 kg
  • MAX SPEED (MPH) 118 mph
  • 0-60 MPH (SECS) 10.4
  • In his seminal work British Leyland: the truth about the cars, Jeff Daniels reports that a 32-valve Stag V8 was created by fitting a pair of Dolomite Sprint cylinder heads and proved to be a potent creation.
  • The V8 engine would have fitted the saloon bodyshell and at least one was built at Triumph… but it never reached production for fear of competing with the Rover 3500.
  • The four-cylinder and V8 were built on the same line and it was said that three four-cylinder engines could be built in the same time it took to assemble a single Stag engine.
  • The fuel injection originally proposed for the Stag engine was to have been Bosch rather than the troublesome Lucas set-up.
  • Alongside the convertible Stag, prototypes of a fastback coupe version were constructed, looking like a big GT6.
  • The Stag name was chosen at random as a secret project name but was adopted by the Board purely because they liked the name.
  • In the early days, the Stag was considered as an alternative to a TR4 facelift and was briefly and confusingly referred to as TR6.
  • The Coventry Climax V8 race engine also fitted the 2000/Stag engine bay and Climax boss Leonard Lee ran the unit in his own 2500 estate.
  • A lowered rear seat pan and floorpans allowed improved legroom in the rear.
  • In theory, the V8 could have been stretched to a maximum four litres.
  • The earliest cars were hand-assembled on the TR6 production line as the Stag track was not yet ready.
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