Welcome to 365 Days of Motoring

An Everyday Journey Through Motoring History, Facts & Trivia

Belt up and enjoy this 365-day ride as you cruise past the most momentous motoring events in history. Packed with fascinating facts about races, motorists and the history of the mighty engine, this is a must-visit web site for any car enthusiast.

On This Day

Friday 13th March 1970

48 years ago

The first production Triumph Stag rolled off the assembly line. Envisioned as a luxury sports car, the Triumph Stag was designed to compete directly with the Mercedes-Benz SL class models. All Stags were four-seater convertible coupés, but for structural rigidity – and to meet new American rollover standards of the time – the Stag required a B-pillar "roll bar" hoop connected to the windscreen frame by a T-bar. A removable hardtop was a popular factory option for the early Stags, and was later supplied as a standard fitment. The car started as a styling experiment cut and shaped from a 1963–64 Triumph 2000 pre-production saloon, which had also been styled by Michelotti, and loaned to him by Harry Webster, Director of Engineering at Triumph. Their agreement was that if Webster liked the design, Triumph could use the prototype as the basis of a new Triumph model. Harry Webster, who was a long time friend of Giovanni Michelotti, whom he called "Micho", loved the design and took the prototype back to England. The end result, a two-door drop head (convertible), had little in common with the styling of its progenitor 2000, but retained the suspension and drive line. Triumph liked the Michelotti design so much that they propagated the styling lines of the Stag into the new T2000/T2500 saloon and estate model lines of the 1970s. The initial Stag design was based around the saloon's 2.5-litre six cylinder engine, but Harry Webster intended the Stag, large saloons and estate cars to use a new Triumph-designed overhead cam (OHC) 2.5-litre fuel injected (PI) V8. Under the direction of Harry Webster's successor, Spen King in 1968, the new Triumph OHC 2.5 PI V8 was enlarged to 2997 cc (3.0 litres) to increase torque. To meet emission standards in the USA, a key target market, the troublesome mechanical fuel injection was dropped in favour of dual Zenith-Stromberg 175 CDSE carburettors. A key aim of Triumph's engineering strategy at the time was to create a family of engines of different size around a common crankshaft. This would enable the production of power plants of capacity between 1.5 and 4 litres, sharing many parts, and hence offering economies of manufacturing scale and of mechanic training. A number of iterations of this design went into production, notably a slant four-cylinder engine used in the later Triumph Dolomite and Triumph TR7, and a variant manufactured by StanPart that was initially used in the Saab 99. The Stag's V8 was the first of these engines into production. Sometimes described as two four-cylinder engines Siamesed together, it is more correct to say that the later four-cylinder versions were half a Stag engine (the left half). It has sometimes been alleged that Triumph were instructed to use the proven all-aluminium Rover V8, originally designed by Buick, but claimed that it would not fit. Although there was a factory attempt by Triumph to fit a Rover engine, which was pronounced unsuccessful, the decision to go with the Triumph V8 was probably driven more by the wider engineering strategy and by the fact that the Buick's different weight and torque characteristics would have entailed substantial re-engineering of the Stag when it was almost ready to go on sale. Furthermore Rover, also owned by British Leyland, could not necessarily have supplied the numbers of V8 engines to match the anticipated production of the Stag anyway.[3] As in the Triumph 2000 model line, unitary construction was employed, as was fully independent suspension – MacPherson struts in front, semi-trailing arms at the rear. Braking was by front disc and rear drum brakes, while steering was power-assisted rack and pinion. The car was launched to a warm welcome at the various international auto shows. The Stag rapidly acquired a reputation for mechanical unreliability, usually in the form of overheating. These problems arose from a variety of causes. First, the late changes to the engine gave rise to design features that were questionable from an engineering perspective. For example, the water pump was set above the engine. If the engine became hot in traffic, coolant escaped from system via the expansion bottle and the overall fluid level then fell below the level of the pump. As well as preventing coolant from circulating, this also caused rapid failure of the pump. Even when the system was topped up again, the failed water pump would not circulate coolant and further overheating ensued. Water pump failures also occurred due to poorly hardened drive gears, which wore out prematurely and stopped the water pump. A second cause of engine trouble was the choice of materials. The block was made from iron and the heads from aluminium, a mixture that required the use of corrosion-inhibiting antifreeze all year round. This point was not widely appreciated either by owners or by the dealer network supporting them. Consequently the engines were affected by electrolytic corrosion, so that corroded alloy debris came loose and was distributed around inside the engine. A third cause of trouble was the engine's use of long, simplex roller link chains, which would first stretch and then often fail inside fewer than 25,000 miles (40,200 km), resulting in expensive damage. Even before failing, a stretched timing chain would skip links and cause valves to lift and fall in the wrong sequence, so that valves hit pistons and damaged both. Another problem with the cylinder heads was the arrangement of cylinder head fixing studs, half of which were vertical and the other half at an angle. The angled studs when heated and cooled, expanded and contracted at a different rate to the alloy heads, causing sideways forces which caused premature failure of the cylinder head gaskets. Anecdotally this arrangement was to reduce production costs as the cylinder head mounting studs and bolt were all accessible with the rocker covers fitted. This allowed the factory to completely assemble the cylinder head assembly before fitting to the engine. However this was not possible in the end due to the cam chain fitting and setting of the cam timing requiring the removal of the rocker covers. Finally, although pre-production engines cast by an outside foundry performed well, those fitted to production cars were made very poorly in house by a plant troubled with industrial unrest and poor quality control. Poor manufacturing standards also gave rise to head warpage, and head gaskets that restricted coolant flow, which also led to overheating. This combination of design, manufacturing and maintenance flaws caused a large number of engine failures. Time magazine rated the Triumph Stag as one of the 50 worst cars ever made. At the time, British Leyland never provided a budget sufficient to correct the few design shortcomings of the Triumph 3.0 litre OHC V8. Another problem was that the Stag was always a relatively rare car. British Leyland had around 2,500 UK dealers when the Stag was on sale and a total of around 19,000 were sold in the UK. Thus the average dealer sold only seven or eight Stags during the car's whole production run, or roughly one car per year. This meant that few dealers saw defective Stags often enough to recognise and diagnose the cause of the various problems. The last production Stag (BOL88V) is kept at the Heritage Motor Centre