The
Triumph Slant-4 is an
engineAn engine is a machine that produces mechanical force and motion from another form of energy . It is also referred to as a prime mover. An automobile makes use of several motors to start the car and drive the car's various pumps – but the power plant that propels the car is called an engine...
developed by
TriumphThe Triumph Motor Company is a defunct British motor manufacturer. The Triumph marque is currently owned by BMW. The marque had its origins in 1885 when Siegfried Bettmann and Moritz Schulte from Germany founded Bettmann & Co and started selling Triumph bicycles from premises in London and from...
. According to Triumph historians Graham Robson and Richard Langworth in
Triumph Cars, the complete story, the engine was developed in-house by a design team led by Lewis Dawtry and Harry Webster.
The UK engineering and consultancy company
RicardoSir Harry Ricardo was one of the foremost engine designers and researchers in the early years of the development of the internal combustion engine....
, which did have a general engine-development contract with Triumph, was not directly involved with its design, but was usually kept informed of anything new being planned.
The
Triumph Slant-4 is an
engineAn engine is a machine that produces mechanical force and motion from another form of energy . It is also referred to as a prime mover. An automobile makes use of several motors to start the car and drive the car's various pumps – but the power plant that propels the car is called an engine...
developed by
TriumphThe Triumph Motor Company is a defunct British motor manufacturer. The Triumph marque is currently owned by BMW. The marque had its origins in 1885 when Siegfried Bettmann and Moritz Schulte from Germany founded Bettmann & Co and started selling Triumph bicycles from premises in London and from...
. According to Triumph historians Graham Robson and Richard Langworth in
Triumph Cars, the complete story, the engine was developed in-house by a design team led by Lewis Dawtry and Harry Webster.
The UK engineering and consultancy company
RicardoSir Harry Ricardo was one of the foremost engine designers and researchers in the early years of the development of the internal combustion engine....
, which did have a general engine-development contract with Triumph, was not directly involved with its design, but was usually kept informed of anything new being planned. Ricardo was involved in developing a new engine for
SaabSaab Automobile AB, better known as Saab, is a Swedish car manufacturer currently owned by General Motors, pending sale to the Koenigsegg Group. It is the exclusive automobile royal warrant holder as appointed by H.M., the King of Sweden...
, as a replacement for their aging
Saab two-strokeThe first Saab two-stroke engine was based on a DKW design. The SAAB engine, a two-cylinder with 764 cc engine displacement and 25 hp was transversally placed in the 1950 - 1956 Saab 92, giving it a top speed of 100 km/h. With the 1954 model engine output was raised to 28 hp...
and
V4The Taunus V4 was a V4 piston engine with one balance shaft, introduced by Ford Motor Company in Germany in 1962. The German V4 was built in the Cologne plant and powered the Ford Taunus and German versions of the Granada, Capri and Transit...
units. When that development proved too expensive and risky to produce, Ricardo, knowing the slant-4 was almost ready for production, brought Saab into contact with Triumph.
Saab first used the Triumph Slant-4 at 1.7 L (1709 cc) for the
Saab 99The 99 is an automobile produced by Saab from 1968 to 1984.- Development :On April 2, 1965, Gudmund's day in Sweden, after several years of planning, the Saab board started Project Gudmund. This was a project to develop a new and larger car to take the manufacturer beyond the market for the smaller...
. Only later, as production capacity increased, did it become available in Triumphs. Development by Saab continued into the 1990s. The engine is a
straight-4The inline-four engine or straight-four engine is a four-cylinder internal combustion engine with all four cylinders mounted in a straight line, or plane along the crankcase. The single bank of cylinders may be oriented in either a vertical or an inclined plane with all the pistons driving a...
with the cylinders tilted at 45 degrees (actually in effect half of the
Triumph V8The Triumph V8 is a 3.0 litre V8 developed in house by Triumph for the Triumph Stag. This was basically two Triumph Slant-4 engines 'stuck' together. It consisted of a single overhead cam cast iron block with aluminium heads.-Development:...
that was used in the
Triumph StagThe Triumph Stag is a British car that was sold between 1970 and 1978 by the Triumph Motor Company styled by the Italian designer Giovanni Michelotti.-Design and styling:...
).
The engine was used by Triumph in the
DolomiteThe Triumph Dolomite was a popular small saloon car made by the Triumph Motor Company division of the British Leyland Corporation in Canley, Coventry in the 1970s and 1980s.-History:...
1850, the Dolomite Sprint, and the
TR7The Triumph TR7 was a sports car manufactured from September 1974 to October 1981 by the Triumph Motor Company, part of British Leyland, in the United Kingdom. It was initially made at the Speke, Liverpool factory, moving to Canley, Coventry in 1978 and finally to the Rover plant in Solihull in 1980...
. It was also used by
PantherPanther Westwinds was a manufacturer of niche sports cars and luxury cars, based in Surrey, United Kingdom. Founded in 1972 by Robert Jankel, the Panther company enjoyed success throughout the 1970s with retro-styled cars based on the mechanical components of standard production cars from other...
in the Dolomite-based
RioThe Panther Rio was an motor car made by British manufacturer Panther Westwinds, using Triumph Dolomite mechanicals. According to the company, it differed from the family saloon-class Dolomite, in being finished to "Rolls-Royce standards". Only 38 were built between 1975 and 1977...
(1975-1977). Triumph ended manufacture of the engine when the TR7 was discontinued in 1981.
Sprint version
Triumph added unique SOHC
4-valveIn automotive engineering, an engine is referred to as multi-valve when each cylinder has more than two valves. Such designs have been around since at least 1912 and perhaps earlier....
cylinder heads to the Slant-4 for 1973's
Dolomite SprintThe Triumph Dolomite was a popular small saloon car made by the Triumph Motor Company division of the British Leyland Corporation in Canley, Coventry in the 1970s and 1980s.-History:...
. This is regarded as the first mass-produced
multi-valveIn automotive engineering, an engine is referred to as multi-valve when each cylinder has more than two valves. Such designs have been around since at least 1912 and perhaps earlier....
car engine.
Saab B engine
Saab later increased the engine size to 1.85 L and in 1972 the company brought production in-house (to Scania) for the
2.0 L B versionThe Saab B engine was created in 1972 when SAAB bought Scania. It was completely built by Saab-Scania, at the Södertälje factory. The design was based on the Triumph Slant-4 engine, but with an increased engine displacement from 1.9 to 2.0 litres. This engine shared much with the original Triumph...
. This engine shared much with the original Triumph design, including bore centers and bearings, but was substantially redesigned. The Saab B engine was replaced by the related
Saab H engineThe Saab H engine is a redesign of the Saab B engine. Despite the name it is not an H engine, but a slanted inline-4. The H engine was introduced in 1981 in the Saab 900 and was also used in the Saab 99 from 1982 onwards and the Saab 90. It continued in use in the 900/9-3, 9000, and 9-5...
.