The Triumph V8 is a 3.0 litre V8 developed and built by the

Triumph Motor Company The Triumph Motor Company was a British car and motor manufacturing company in the 19th and 20th centuries. The marque had its origins in 1885 when Siegfried Bettmann of Nuremberg formed S. Bettmann & Co. and started importing bicycles from Eu ...

for the

Triumph Stag The Triumph Stag is a 2+2 sports tourer which was sold between 1970 and 1978 by the Triumph Motor Company, styled by Italian designer Giovanni Michelotti. Design and styling Envisioned as a luxury sports car, the Stag was designed to compete ...

. The engine was a development of the

Triumph slant-four engine The Triumph slant-four is an inline four-cylinder petrol car engine developed by the Triumph Motor Company. It first appeared in 1968 in the Saab 99. The first Triumph model to use the engine did not appear until 1972. With an original capacit ...

. It consisted of a cast iron block and aluminium cylinder heads with a

single overhead cam An overhead camshaft (OHC) engine is a piston engine where the camshaft is located in the cylinder head above the combustion chamber. This contrasts with earlier overhead valve engines (OHV), where the camshaft is located below the combustion c ...

per bank.

Development

The Stag was developed between 1964 and 1969. Whilst originally seen as little more than a

convertible A convertible or cabriolet () is a passenger car that can be driven with or without a roof in place. The methods of retracting and storing the roof vary among eras and manufacturers. A convertible car's design allows an open-air driving expe ...

version of the

Triumph 2000 The Triumph 2000 is a mid-sized, rear wheel drive automobile which was produced in Coventry by the Triumph Motor Company between 1963 and 1977. It was introduced on 15 October 1963. It was styled by Giovanni Michelotti. It competed with the c ...

saloon, as development progressed the Stag gained its own identity until the final design shared no body panels or pressings with the 2000. The Stag was intended to use Triumph's existing 2.5-litre straight-6 engine. When the Stag design evolved into a

grand tourer A grand tourer (GT) is a type of car that is designed for high speed and long-distance driving, due to a combination of performance and luxury attributes. The most common format is a front-engine, rear-wheel-drive two-door coupé with either ...

rather than a more conventional

sports car A sports car is a car designed with an emphasis on dynamic performance, such as handling, acceleration, top speed, the thrill of driving and racing capability. Sports cars originated in Europe in the early 1900s and are currently produced by ...

it became clear that a more powerful, more refined engine was needed. As far back as 1963 the designer of the

Triumph Slant-4 engine The Triumph slant-four is an inline four-cylinder petrol car engine developed by the Triumph Motor Company. It first appeared in 1968 in the Saab 99. The first Triumph model to use the engine did not appear until 1972. With an original capacity ...

, Lewis Dawtrey, had foreseen the possibility that the engine design could be 'doubled-up' to create a V8 unit. This was not a unique approach; Vauxhall had followed a similar strategy, designing its own slant-4 so that two could be joined to make a V8 (which, ultimately, Vauxhall did not pursue). Whilst at this point the engine had only been produced in 1.7-litre form by Triumph for sale to

Saab Saab or SAAB may refer to: Brands and enterprises * Saab Group, a Swedish aerospace and defence company, formerly known as SAAB, and later as Saab AB ** Datasaab, a former computer company, started as spin off from Saab AB * Saab Automobile, a fo ...

, the basic design of the engine enabled capacities as low as 1.2-litres to be built. Triumph revived the V8 concept, initially settling on a 2.5-litre engine (in essence two 1.2-litre versions of the slant-4) with mechanical

fuel injection Fuel injection is the introduction of fuel in an internal combustion engine, most commonly automotive engines, by the means of an injector. This article focuses on fuel injection in reciprocating piston and Wankel rotary engines. All comp ...

provided by Bosch. Following the take-over of Triumph by

Leyland Motors Leyland Motors Limited (later known as the Leyland Motor Corporation) was a British vehicle manufacturer of lorries, buses and trolleybuses. The company diversified into car manufacturing with its acquisitions of Triumph and Rover in 1960 and 1 ...

in 1967

Spen King Charles Spencer "Spen" King (26 March 1925 – 26 June 2010) was a significant figure in the Rover Company and, after their takeover, in the British Leyland Motor Corporation.After leaving school in 1942, he was first apprenticed to Rolls-Royc ...

was placed in charge of product development at Triumph. The V8's Bosch fuel injection was running into numerous difficulties in development and King was unable to convince Leyland to divert extra funds to Triumph to solve the problems. Instead, King dropped the fuel injection in favour of twin Zenith-Stromberg

carburetor A carburetor (also spelled carburettor) is a device used by an internal combustion engine to control and mix air and fuel entering the engine. The primary method of adding fuel to the intake air is through the venturi tube in the main meteri ...

s. To maintain the required power output the capacity was increased to 3-litres, which then entailed modification to the Stag's other drivetrain systems including the

gearbox Propulsion transmission is the mode of transmitting and controlling propulsion power of a machine. The term ''transmission'' properly refers to the whole drivetrain, including clutch, gearbox, prop shaft (for rear-wheel drive vehicles), differe ...

, back

axle An axle or axletree is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In the former case, bearing ...

and

brake A brake is a mechanical device that inhibits motion by absorbing energy from a moving system. It is used for slowing or stopping a moving vehicle, wheel, axle, or to prevent its motion, most often accomplished by means of friction. Background ...

s. This relatively 'last-minute' capacity increase was achieved by expanding the bore of the engine instead of the stroke, which explains the Triumph V8's unusual 'oversquare' internal dimensions.

Design

As launched in 1970 the Triumph V8 had several innovative features. As well as its unusual construction (the

crankcase In a piston engine, the crankcase is the housing that surrounds the crankshaft. In most modern engines, the crankcase is integrated into the engine block. Two-stroke engines typically use a crankcase-compression design, resulting in the fuel/a ...

and

cylinder block In an internal combustion engine, the engine block is the structure which contains the cylinders and other components. In an early automotive engine, the engine block consisted of just the cylinder block, to which a separate crankcase was attac ...

were made from chromium iron whilst the

cylinder head In an internal combustion engine, the cylinder head (often abbreviated to simply "head") sits above the cylinders and forms the roof of the combustion chamber. In sidevalve engines, the head is a simple sheet of metal; whereas in more modern ov ...

s were aluminium alloy), the engine featured a unique arrangement of studs and bolts attaching the cylinderheads that allowed the cylinderheads to be removed (in design, not in reality) without firstly removing the

overhead camshaft An overhead camshaft (OHC) engine is a piston engine where the camshaft is located in the cylinder head above the combustion chamber. This contrasts with earlier overhead valve engines (OHV), where the camshaft is located below the combustion c ...

s and disturbing the valveplay adjustment. The water pump, oil pump and

distributor A distributor is an enclosed rotating switch used in spark-ignition internal combustion engines that have mechanically timed ignition. The distributor's main function is to route high voltage current from the ignition coil to the spark plugs ...

were all driven at their required speeds from a single jackshaft driven from the

timing chain In a piston engine, either a timing belt (also called a ''cambelt'') or timing chain or set of timing gears is used to synchronize the rotation of the crankshaft and the camshaft. This synchronisation ensures that the engine's valves open and cl ...

via sets of skew-cut gears. The cooling fan was a 16-blade plastic item driven through a hydraulic viscous coupling that limited fan speed to 2,500 rpm to reduce noise as well as controlling the fan speed in relation to engine temperature.

Potential other uses

Triumph originally intended their V8 to be used across their range, which was the reason for the company's willingness to fund the engine's high development costs. Plans were made to create a 'Triumph 3000' by fitting the engine into the 2000 saloon, but these plans were halted when Rover joined Triumph in the Leyland grouping as the resulting car would have been a direct competitor for the Rover 'P6' 3500. Triumph also tried to sell the engine to the

Morgan Motor Company The Morgan Motor Company is a British motor car manufacturer owned by Italian investment group Investindustrial. It was founded in 1910 by Henry Frederick Stanley Morgan. Morgan is based in Malvern Link, an area of Malvern, and employs appr ...

but that company chose the

Rover V8 The Rover V8 engine is a compact V8 internal combustion engine with aluminium cylinder block and cylinder heads, originally designed by General Motors and later re-designed and produced by Rover in the United Kingdom. It has been used in a wide ...

as well.

tested the V8 in the

Saab 99 The Saab 99 is a car which was produced by Saab from 1968 to 1984; their first foray into a larger class than the 96. While considered a large family car in Scandinavia, it was marketed as a niche compact executive car in most other markets. It w ...

mainly for US markets but the oil crisis in 1973 finally caused cancellation of the project in favour of

turbocharging In an internal combustion engine, a turbocharger (often called a turbo) is a forced induction device that is powered by the flow of exhaust gases. It uses this energy to compress the intake gas, forcing more air into the engine in order to pro ...

. The result was the V8 remained unique to the Stag.

References

* Observer's Book of Automobiles P. Olyslager. 1972 Frederick Warne, London. * Taylor, J, 1983 "Triumph Stag - Super Profile", Haynes Publishing, UK. * Lindh, B-E, 1987 "Saab The first 40 years", Förlagshuset Norden AB, Sweden. {{ISBN, 91-86442-34-1 V8 Gasoline engines by model V8 engines

Development

Design

Potential other uses

See also

References