The Triumph Six Cylinder or Triumph I6 engine is a

cast-iron Cast iron is a class of iron–carbon alloys with a carbon content of more than 2% and silicon content around 1–3%. Its usefulness derives from its relatively low melting temperature. The alloying elements determine the form in which its car ...

overhead valve An overhead valve engine, abbreviated (OHV) and sometimes called a pushrod engine, is a piston engine whose valves are located in the cylinder head above the combustion chamber. This contrasts with flathead (or "sidevalve") engines, where the v ...

straight-six engine A straight-six engine (also referred to as an inline-six engine; abbreviated I6 or L6) is a piston engine with six cylinders arranged in a straight line along the crankshaft. A straight-six engine has perfect primary and secondary engine balanc ...

produced by

Standard Triumph The Standard Motor Company Limited was a motor vehicle manufacturer, founded in Coventry, England, in 1903 by Reginald Walter Maudslay. For many years, it manufactured Ferguson TE20 tractors powered by its Vanguard engine. All Standard's tract ...

. It is an evolution of the

Standard Motor Company The Standard Motor Company Limited was a motor vehicle manufacturer, founded in Coventry, England, in 1903 by Reginald Walter Maudslay. For many years, it manufactured Ferguson TE20 tractors powered by its Vanguard engine. All Standard's tracto ...

inline-4 A straight-four engine (also referred to as an inline-four engine) is a four-cylinder piston engine where cylinders are arranged in a line along a common crankshaft. The majority of automotive four-cylinder engines use a straight-four layout ( ...

SC engine originally designed for the

Standard Eight The Standard Eight is a small car produced by the British Standard Motor Company from 1938 to 1959. The car was originally launched in 1938 as the Flying Eight. After the Second World War the Flying range of Standards was dropped but an update ...

, with the addition of two cylinders and a larger displacement. Introduced in their Standard Vanguard Six in 1960, it was used in a wide range of Triumph vehicles, including the

Triumph TR5 The Triumph TR5 is a sports car built by the Triumph Motor Company in Coventry, England, between August 1967 and September 1968. Visually similar to the Michelotti-designed TR4 open two-seater it was derived from,TR for Triumph, Chris Harve ...

, TR250, and TR6.

Origin

Standard Six engine

The six cylinder engine was developed from the Standard SC four and was first used in 1960 in the Standard Vanguard Six, in which it had a bore and a stroke, giving a capacity of 1998 cc. It was also used in the Eight and the Ten. The engine was next used in the

Triumph Vitesse The Triumph Vitesse is a Compact car, compact six-cylinder car built by Triumph Motor Company, Standard-Triumph from 1962 to 1971. The car was based on the Giovanni Michelotti designed Triumph Herald, Herald and was available in Sedan (automobi ...

, a sports saloon based on the Herald, in 1962. In this application, the engine had a bore, reducing displacement to 1596 cc. The Vitesse was given the two-litre engine with the 74.6 mm bore in 1966. 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 co ...

replaced the Vanguard Six in 1963 when Leyland discontinued the Standard marque. The two-litre six was later used in the

Spitfire The Supermarine Spitfire is a British single-seat fighter aircraft that was used by the Royal Air Force and other Allied countries before, during, and after World War II. It was the only British fighter produced continuously throughout the ...

-based GT6 coupé from 1966 to 1974. Beginning in 1967, the engine was used in the

and TR250 sports cars, replacing the

Standard inline-four engine The Standard wet liner inline-four engine was an inline four cylinder petrol engine produced by the Standard Motor Company. Originally developed concurrently for passenger car use and for the Ferguson TE20 tractor, it was widely used for Standar ...

used in TRs from the TR2 to the TR4A. For this application, the stroke was increased to , giving 2498 cc. When equipped with the Lucas mechanical fuel injection system in the TR5, this new 2.5-litre version gave a claimed at 5500 rpm. When tested on dynamometers, 110 to 130bhp at the crankshaft is more usual, and may explain Triumph's decision to fit the TR7 with a 2-litre slant-four engine, whose power output and hence performance were in fact similar to those of the earlier and ostensibly more powerful engine. The TR250 was sold in the US with Stromberg carburettors to avoid the need for additional emissions control systems; this reduced the power to at 4500 rpm. The TR6, made from 1969 to 1975, used the TR5's engine, detuned to in 1973. with a 106 hp version of the TR250's engine in the United States. The fuel-injected 2.5 litre engine became available in the 2000 unit body as the 2.5 PI in 1968; this was supplanted by the twin-carburettor 2500 TC in 1974. The 2000 and 2500 TC were discontinued in 1977.

Technical

A partial chart of Triumph engine numbers is posted on the "Spitfire & GT6 magazine" site. However the capacity appears not to match the bore/stroke, or that published on other sites including the GT6 Ezine, hence the corrections in the tables below. Engine Applications Chart Factory Quoted Power Chart

Racing

Triumph raced Spitfires, and some early GT6 prototypes at Le Mans, with some good success, and later at Sebring but due to rule changes and the takeover by Leyland, this was not continued.

Replacement

After Triumph, and later

Rover Rover may refer to: People Name * Constance Rover (1910–2005), English historian * Jolanda de Rover (born 1963), Dutch swimmer * Rover Thomas (c. 1920–1998), Indigenous Australian artist Stage name * Rover (musician), French singer-songw ...

, were absorbed into Leyland Motors in 1960, and 1967 respectively, work began on a successor to both the

and the

Rover P6 The Rover P6 series (named as the 2000, 2200, or 3500, depending on engine displacement) is a Sedan (automobile), saloon car produced by Rover Company, Rover and subsequently British Leyland from 1963 to 1977 in Solihull, West Midlands, England, ...

which would also use a new straight six engine design. The engine, known internally as the Leyland PE166 was originally intended to be a development of the Triumph I6, but ended up becoming an entirely new design, with almost no interchangeable parts with the original. The

Rover SD1 The Rover SD1 is both the code name and eventual production name given to a series of executive cars built by the Specialist Division (later the ''Jaguar-Rover-Triumph'' division), and finally the Austin Rover division of British Leyland from 1 ...

was the only recipient of this engine in both 2.3L and 2.6L capacities.

Notes

References

* * *{{cite book, last = Robson, first = Graham, title = The Book of the Standard Motor Company, url = {{Google books, LbCIGEFLi_kC, The Book of the Standard Motor Company, plainurl=yes , access-date = 19 October 2014, date = May 2011, publisher = Veloce Publishing, location = Poundbury, Dorchester, UK, isbn = 978-1-845843-43-4 I6 Standard Motor Company engines Straight-six engines Gasoline engines by model