The TR3b was a North American-only update of the successful TR3a, and was never officially available in the UK, although a few have since been re imported.
Triumph never intended to produce another side-screen car after the TR3a, but initially the North American dealers displayed doubt about the all-new, sophisticated TR4, with its wind-up windows and full width bodywork. They feared that it was too modern, recalling the enormous number of TR3as sold in the late fifties. To appease the North American dealers Standard-Triumph decided to produce one last batch of TR3's, in part to use up the supply of TR3a bodies that were still lying around the Canley factory. The TR3b was produced from March 1962 until October 1962; six months after the last TR3a had been manufactured in the previous October. The supply of bodies ran out shortly after the 3,331st TR3b had been completed, making this one of the rarest of the TR-family.
The TR3bs were produced by the Forward Radiator Company, using the same tooling that the parent company Mulliner had used to produce the TR2 and TR3. The first five hundred cars were virtually the same as the TR3a, the only difference being the TSF commission number and the gearbox - they all had the 1991cc engine coupled to the all-synchromesh TR4 gearbox. Although the layout of the gearbox remained the same, the extra space needed for the first gear synchromesh meant that it had to have a new aluminium casing which was not interchangeable with the non-synchromesh box .The TSF models are nice cars and very rare, but of greater interest is the TCF series.
The TCF-series TR3b is probably the nicest of the side-screen cars, and by far the most sought after. Fitted with the 2138cc TR4 power plant and all-synchromesh gearbox, it had the best combination of drive-train and was the only pre-TR4 with this combination. The gear ratios were changed to match the 2.2 litre engine which produced more torque than the 2 litre unit. The gearbox remote was also modified to reduce the play in the gear linkage. Most of the TR3a specification was unchanged including the overdrive unit and front wheel disc brakes, which had been introduced in 1957.
Not a lot is known about the TR3b, the specification varied according to whatever parts were left over from TR3a production. There were some very unusual colour schemes, and even strange trim combinations.
TSF1 to TSF530 (all-synchromesh gearbox)
TCF1 to TCF2804 (TR4 Engine and all-synchromesh box)
Triumph TR3B - Updated - March 2015
Towards the end of last year we - the TRDC - were contacted by Frank Marsden. Frank, an employee of Standard Triumph back in the day, had read about the TR3 BETA on our web-site and wanted to let us know the information we'd posted wasn't entirely correct. The generally accepted raison d'etre for the TR3 BETA was to make the improved TR4 chassis, suspension and mechanicals fit under a widened TR3 body; whereas in fact the TR3 BETA came first. Frank was part of the team assembled under Ray Bates [who would later become Standard Triumph Technical Engineer] and initially installed at the Radford factory. It was when the team was re-located back to Fletchampstead North [a part of the Canley HQ] that he was given the job of widening the track of the TR3. No reason was given to him for this instruction but I suspect it was because the standard TR3 chassis wasn't ideal, and although the car was much quicker than the competing MGAs of the period it couldn't keep up when it came to progress on twisty, winding country roads. Thus the widened version of the TR3 was created - TR3 BETA. Two cars were built, one in black and the other in red, and both vehicles survive today.
When Frank was working on the TR3 BETA project it was simply designated as a TR3B - the same nomenclature as that ultimately adopted for the updated TR3A destined for the North American market, despite the fact that both the TR3A and TR3B monikers were never officially adopted by the factory. Just so we're very clear, what is known as the TR3B and the TR3 BETA were completely different vehicles, and apart from their obvious Triumph TR3 heritage they were definitely not related projects.
Gordon Birtwistle [the Standard Triumph High Speed Development Engineer] has told us he did a lot of testing at MIRA in the black car, affectionately known as 'Black BETA'. The original concept to improve the handling of the TR certainly worked and hence the new TR4 used the chassis, suspension and mechanicals as developed for the TR3 BETA.
So there we are - it just goes to show that what you read in the motoring press is not always entirely correct. During the interview, Frank also revealed that he was involved in work on the Le Mans TR4S cars [more commonly known today as "TRS"], but perhaps that's another story for another time. JC\AP