TR250 and TR6: Six Cylinders Replace Four
The late 1960s saw the introduction of two new Triumph models: the Triumph TR250 and the Triumph TR6.
For 1968, the newfangled U.S. exhaust-emission regulations began to bite, so Triumph's managers had to think hard about the Triumph TR's future. They concluded that a new engine and fresh styling were needed. Indeed, the old wet-liner four-cylinder engine was overdue for replacement, so the company decided to replace it with a version of the overhead-valve six already found in its 2000, GT6, and Vitesse (Sports Six to Americans) models.
The 1968 Triumph TR250 was fitted with a
six-cylinder engine based on the overhead-valve
unit in Triumph's sedans.
With a longer-throw crankshaft, modified cylinder block, and a more efficient cylinder head, it became a smooth and silky 152.4-cid (2498-cc) unit. In fact, 121-cid sixes had been running round in prototype TR4s since 1962.
First thoughts were to equip the Stateside version with Lucas fuel injection, but when Triumph discovered that it could not meet the new emissions legislation, conventional Zenith-Stromberg carburetors were fitted instead.
Thus equipped, and with 111 horsepower (U.S. spec, only fractionally more than the old 130.4-cid TR4A), the re-engined TR4A was badged TR250 for its engine size, and sold only in North America. This time the dealers were told quite firmly that they could no longer have a rigid-rear-axle alternative, and henceforth all cars would have the semi-trailing link independent rear suspension.
The "Rest of the World" version of the TR250 was equipped with Lucas injection, boasted no less than 150 horses, and was logically badged TR5 PI ("Petrol Injection"). America's loss was the Europeans' gain, for this car (and the rest-of-the-world TR6 that followed) was a genuine 120-mph machine, very fast off the line, and full of "hairy-chested" character.
Although the TR250 looked like the TR4A and the obsolete TR4 -- sheetmetal was unchanged -- detail differences gave it away. Inside, the dash lost its polished walnut, while gauge bezels and switches and knobs took on a "safety" dull finish. Further, the generous dash-mounted fresh-air vents became small "eyeball" outlets and seat facings were now vinyl instead of leather.
Most noticeably, however, the TR250 got a transverse triple racing stripe across its nose (like an American muscle car). In addition, the convertible top wore reflective tape strips at sides and rear, and the wheels were covered with fake "Rostyle" hubcaps, which Road & Track said "are perfectly acceptable in appearance. ..." Wire wheels cost $118 extra, and real alloy wheels were also available. Road & Track also commented that the new six provided "a nice increase in torque ... which gives the engine an appreciably greater amount of smooth, low-speed pulling power. As it stands, the engine is in a very mild stage of tune and could hardly run more sweetly."
On the other hand, there was "a body structure well behind modern standards in terms of strength and resistance to rattles. An entirely new model would have been more exciting to us and to the customers, but the British car industry moves slowly these days. ..."
All of the superficial changes to the TR250 didn't matter too much, however, for a restyled TR was on the way. Well before the launch of the TR250, Triumph had again turned to Michelotti to produce a sorely needed major facelift. But the Italian pointed out that he was far too busy working on the revised Triumph 2000, a reskinned Spitfire/GT6, the Stag, and on new small sedans -- and he still had a very small studio in Turin. Triumph had no choice but to look elsewhere.
The 1972 Triumph TR6 wore a black-out grille
that separated widely spaced headlights.
At the same time, Karmann, the West German concern famed for building the Volkswagen Karmann-Ghia, was looking for additional work. The firm approached Triumph, and was rewarded not only with the tooling contract for a modified TR250, but the styling job as well. The result, unveiled in January 1969, was the TR6, a car that retained the TR250's chassis, center body structure, and many inner panels, but featured completely new front and rear ends, plus cleaner looks.
Instead of a nose with protruding headlamp eyebrows, there was a smoother outline; a sharply cut-off, Kamm-style rear end was adopted in lieu of a more conventional tail. A new type of optional hardtop was also specified, which meant that the famous old two-piece Surrey option was gone.
This, then, was the last of the body-on-frame TRs, which went on to become the most successful and longest-lived of them all. In production from the end of 1968 until the summer of 1976 (actually overlapping the totally different unibody TR7 by nearly two years), it was changed only to keep abreast of U.S. safety and emissions regulations.
Today, if you compare a 1969 TR6 with a 1976, you would notice different engine details and gear ratios, changes to the fuel tank, wheels, steering wheel, trim, and furnishings -- and no one could possibly miss the five-mph rubber overriders added front and rear. Some of the biggest changes came for '71, when the compression ratio dropped from 8.5:1 to 7.75:1, slightly blunting performance. And ride height had to be raised to meet headlight height requirements, which hurt handling. Nineteen seventy-one was also the last year for the classic-look wire wheels.
In seven years, though, TR6 performance had changed very little despite ever-tougher emissions standards, which is more than could be said for some of its rivals, which suffered badly (particularly the MGB). Even after the six-cylinder engine was introduced for 1968, Triumph fought to keep the power output at its pre-emissions level, and pretty much succeeded. The last of the TR4As produced 104 bhp -- and in 1976 the last of the TR6s produced 106 bhp. Admittedly, the engine had grown by 22 cubic inches, but this was almost inevitable, as Detroit's Big Three also found out.
Before the TR6 finally disappeared, there was time to reflect on the way the entire character of the TRs had changed since 1953. Naturally, the styling was more graceful, and the level of equipment was more complete, but the last of the body-on-chassis TRs was very different from the original. It was faster (but not by all that much), smoother, and softer in so many ways, but was it really any more of a sports car?
Strange to relate, when the TR4 took over from the TR3A, some writers thought Triumph had gone soft, but by the Seventies the same pundits were referring to the TR6 as the "last of the hairy-chested sports cars."
The very last TR6s were assembled in July 1976, and, given shipping times, a few of these may have been titled as 1977s. After this, TR enthusiasts were obliged to consider the wedge-shaped TR7 instead (many wouldn't), or an MGB, which became history in October 1980. But for the separate-chassis Triumph TRs, it was the end of an era, an amazing period covering 23 years of the Coventry company's often stormy history.
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