My main memory of reading about the new TR-250 was: we got cheated! While the rest of the world got the TR-5, with its new 2.5 L inline six sporting fuel injection and making 150 hp, we got the TR-250 with a de-smogged version of the six, but with special emission-friendly Stromberg carbs and rated at 111 hp. Such was life in the country that was leading the way in emission controls: doing the right thing often has a price.
The TR-250 was only built for one year and 8,484 times, replaced by the TR-6, whose restyle I had mixed feelings about. I preferred the original TR-4 style, and the TR-250 and TR-5 were obviously transitional vehicles. The 2.5 L six was a decided improvement over the rather hoary 2.2 L four, so even in TR-250 guise, there was plenty of praise.
The TR-250’s hp increase over the TR-4A was only 6 ponies, but torque significantly more bounteous, rising from 128 lb.ft to 152, and at a lower (3000 instead of 3350) rpm. That combined with the Triumph six’ inherent smooth ways made a marked improvement in feel and acoustics, even if objective performance wasn’t really much better.
The 2.5L six was of course an evolution of the 2.0L six, with a longer stroke and new head with bigger valves. There was considerable space given to its emission scheme, which was similar to the Clean Air Package pioneered by Chrysler, along with a variations. The net effect was…effective, as it avoided most of the driveability issues as well as the need for an air pump.
There were a number of other minor improvements for safety and ergonomics in the cockpit and in other places, like the elimination of the knock-off spinners and such.
The TR-250 (and TR-5) came standard with the IRS that had been offered on the TR-4A for a few years, and in general it worked well enough to make it a decent handler if not exactly a brilliant one. The lack of a rigid body structure (these were all Body On Frame cars) worked against it somewhat, and R&T noted that truly new Triumph would have been a much more exciting reality. It would be a long wait for that, and when it finally arrived, in the form of the TR-7, the enthusiasm was less than full-bore.
I never knew there were emission requirements in place in 1967 that’d have strangled 25% of the horsepower from anything. Detroit muscle was still very much on its way up. That said, the 5 years from 67-71 with a peak in 1970 really did see horsepower that took 30 years to get back.
This TR is not as good looking to me as the TR-6, which I think is very handsome.
It wasn’t just the emission controls. The TR-5 had Lucas mechanical fuel injection and a higher (9.5:1) compression ratio. The decision to use carbs for the US-bound TR-250 was not only driven by emission controls, but also by price. The sports car market was very big and competitive in the US, and the Lucas injection system, like all FI back then, was expensive.
In the UK and the rest of Europe, cars like the TR-6 were essentially in a higher price class than in the US (less affordable) so maximum performance was more critical. Also, it’s possible that the Lucas FI unit was not available in larger volumes.
The same situation continued on with the TR-6: the US version had essentially the same carb engine as the TR-250, but now with only 104 hp, while the European version had the same 150 hp FI unit as the TR-5.
PI or FI was still new tech for America. Suspect Truimph knew that if the car needed servicing outside their meager dealer network a mechanic would open the hood,throw up their arms in horror and then walk away.
Even within Triumph’s dealer network, if the metering unit for the fuel injection developed a problem, it would be replaced, not fixed.
A real in-between model. Although I like the 6 engine (had several saloons with the engine, and lots of experience with a friends TR6), I prefer the 4 cilinder version of the TR4(A). Yes, it is a bit more raw but that makes the car more lively, less modern, more dare I say it, manly.
I am not a fan of the modernization of the TR4s successors. More plastic in the interior, details like door handles, non spoked steering wheel, badges and so on are more modern but have less character. Also, the rear cart springs of the TR4 do their work well. Racers often cho(o)se the TR4 instead of the 4A because of the more predictable rear handling. A further advantage for an owner like me is that the TR4 chassis is stronger (a 4A / 5 / 250 / 6 chassis is quite rust prone at the A arms attachments) and never trouble with the U/Js on the drive shafts – a Triumph weak point on their IRS models.
It is always unfair to compare different generations of cars, the newer car always would and should have improvements! but give me a nice TR4 any day even though a 5 / 250 may have a higher value in the market now.
Premium fuel required at 8.5:1 ???
Since USA doesn’t have the UK tax on cylinder bore size, these cars should have had a big bore short stroke 3.0L. (DOHC optional) 4 banger with flat plane crank and 180 (225) HP !!!
To hell with car magazines wanting smoother engines in sports cars…
I don’t mind the Pontiac Iron Duke 2.5L 4 in my ’85 Fiero and ’77 Astre Formula wagon…
And to hell with car magazines wanting full size cars to ride like dump trucks and handle like Ferraris…
I had a dark blue Belgian TR6 PI import and soon understood why the rear panel was black, the Lucas fuel injection sooted like hell, every three months I had to dismantle the taillights and clean them. The gearbox and diff were sla, fortunately there was an oasis of 2500 saloons in the scrapyards so parts were no problem.
The fuel pump was a disasterous piece of equipmemt and it was very normal to have it replaced by a Bosch unit from a BMW 2800 or 3 liter injection which gave a solid fuel pressure.
One day an older guy offered me a very good price for the car, for half the money I knew a 75 US spec MGB for sale which I bought.
The TR6 was a beast, the MGB the far better car.
US buyers weren’t as cheated as the published numbers suggested. The TR5 and the early (non-US) TR6s were rated at 150 hp but suspicions this might be optimistic were confirmed by later tests.
https://nihilistnotes.blogspot.com/search?q=Scuttle
The wood dash panel with just the right number of gauges always looked miles better to me than its MG counterpart. Also, those headlights peering out from under the hood have a light hearted japanese kei car vibe from the same era.
Stay with the 250, I say.
Do you really want your fuel pumped at 110psi by a wiper motor, that, to the surprise of no-one at all, got very hot right next to your 10 gallons imperial of super? The (fire) saving grace was that the blighter would give up before self-immolating, causing only a safer but still-exasperating failure-to-proceed instead. Or perchance a fuel distributor that didn’t always share as it should’ve, to injectors too often a bit reluctant to play? All for just 25 bhp and a badge?
Jokes aside – though certainly not beyond this comment – it’s clear from looking at the Lucas set-up that it was fairly ingeniously created for a price, and for that, it’s really pretty good. The superior Kugelfischer injection jobbie, for example, is lovely and reliable engineering, but it must have cost an absolute bomb. These Triumphs were never terribly expensive cars, and that’s especially relevant to the massively competitive US market.
Say, talking of bombs, there’s got to be another Lucas injection smarty-pants line there somewhere…
Ok, didn’t even last one post.
Years ago I had a reprint of an Australian road test of a Peugeot 504. I don’t think their test car had fuel injection, but they said the 504 was available with Kugelfischer injection in Australia. IIRC it didn’t yield a lot more power but did yield a fair amount more torque.
Quick question: is there any way to increase the hp of either the TR5 or TR6 back to its 150hp using a different set of carbs/FI? Also, how does the absence of lead nowadays affect the engine – does it need to be converted or can you put additivies into the tank?