This article discusses the famous, or possibly, infamous engine – the Triumph V8.
During the 1960s, Triumph decided to build a ragtop based on the 2000 saloon. The original plan was to use the 2 and 2.5 litre engines that were available in the Triumph parts bin, however as development continued and the car morphed from being a convertible saloon into an open grand tourer – the Stag, the company decided that a bigger engine was required. If the company wanted to crack the US market, a V8 was a must have.
During the early 1960s Triumph had developed a 1700cc 4 cylinder motor for SAAB who paid for its development and was first seen in the SAAB 99 late in the decade before being slotted into the Triumph Dolomite from about 1972. The engine had now grown to an 1850cc inline 4 configuration slanted at 45° producing around 90hp and it became known as the Triumph Slant 4 motor.
When Triumph needed a V8, they took the Slant 4, reduced the size down to a 1250cc and bolted two together to get a 2.5 litre V8 using Bosch fuel injection. Unfortunately Triumph had problems making this all work, so they dropped the fuel injection in favour of classic carburettors by Zenith Stromberg. This lead to a reduction in power, so Triumph increased the size of the cylinders to make a 3-litre version. It was this version that ended up in production.
Why did I call this engine infamous at the beginning? Well for a number of reasons, mostly to do with reliability. Some of the reliability issues were found to be in the design however some were quite simply production issues due to a) the bean counters changing things for cost improvements and b) the “unenthusiastic” line workers. Remember, this was at the height of labour unrest in the British motor industry!
By this stage Standard Triumph had been bought by Leyland and the decision to increase the bore of the motor and not the stroke, meant that the water coolant channels were reduced in size. This, along with unreliable water pumps, casting issues and a production issue with the heads where they were cast in aluminium whilst the block and crankcase were made out of chromium iron. The heads warped under the excess heat generated by the engine, causing it to overheat – not a bad feat in the cooler Northern Europe climate!
Some owners also felt that the timing chain was badly designed and should have been shorter. The chain had a limited life and when it failed it caused a major implosion in the motor. Like comedy, timing is everything! What else …. the main bearings weren’t up to the job either and needed replacing on a regular basis, which was an expensive exercise. This fault was a metallurgic one rather than a design issue. The metals used could have been better quality.
At the time that the Stag and the V8 were under development, Triumph’s owners Leyland, bought Rover. This new sister brought with it a competing V8 and Triumph, who had dumped some serious cash into development, were reluctant to drop theirs in favour of the Rover engine. Both motors put out about 140hp and were similar sizes. I read an article recently that suggested that Rover were reluctant to increase production for the Stag, so both sides of the company were at odds from day one. Interestingly, one of the Rover managers involved in their V8 development also became the head of the Triumph V8 program. Conspiracy theorists could have a field day with that perceived conflict!
Soon after the Stag was launched, British Leyland started getting into financial difficulties and the V8 literally stagnated – very little ongoing development was done and no ironing out of the design features it experienced! Only about 25,000 Stags were produced and the V8 never went into any other BL model – the Rover V8 was used instead. Due to its reliability issues, some Stags (estimated to be about 10% of production) were modified to take Ford V6s or Rover V8s by their owners. This was something that Triumph engineers reckoned couldn’t be done.
Today the Stag is a classic car and the loyal owners have worked out many solutions to the solvable problems. The overheating was cured by an engineer who discovered that one of the hoses used in production was wrong – a cheaper part was fitted instead. When fitting a correctly designed hose, the water flow was greatly improved thus reducing pressure on other parts of the system!
Some of the unreliability was also put down to the service mechanics who weren’t trained properly to keep them running. Like all motors, they need to be serviced properly although I think the main issue was that the V8 didn’t get enough development and testing before going into production.
The Stag lasted only seven years in production and was never replaced, with the V8 sadly dying with the car. Vehicles with matching numbers are now commanding a good price on the market – there is now a clear price distinction between a car with an original V8 and one that has a Ford or Rover unit fitted.
I wonder if whether the 1973 fuel crisis hadn’t happened, this V8 would have been put into other models and had the extra development it needed. I read an article that said that Triumph had tried to sell the V8 to Morgan (for the Plus 8) and that SAAB had tested it in one of their cars, however they chose the turbocharging path instead due to the concerns around global fuel prices.
The Triumph V8 could be compared with the Buick V8 that Rover and Repco made work though better development – more time and funding could have changed everything.