TVR Speed Twelve engine
Encyclopedia
The TVR Speed Twelve engine is the name of a V12 engine
manufactured by TVR
for use in the TVR Speed 12 race car, and later the TVR Cerbera Speed Twelve road car in which on the Cerbera Speed 12 went into production.
The engine was developed by essentially joining two Speed Six
engine blocks to a common crankshaft. The completed engine displaced 7.7 liters and was originally developed for racing applications in TVR's Speed Twelve. Later on, a version was developed for the prototype of a road car to be called the Cerbera Speed Twelve.
Unusually for an automobile, the Speed Twelve's engine block was not constructed of cast iron
or aluminum alloy
, but rather of steel
.
The racing version of the engine produced approximately 675 bhp with its power limited by the intake restrictors required by racing regulations. For the road-version of the engine, the restrictors were not needed so the engine was developed without them. According to reports from TVR engineers, the de-restricted engine snapped the central shaft of their 1000 bhp-rated dynamometer
during the bench-test. The engine's output was later estimated (conservatively) at 940 bhp. When the prototype vehicle was road-tested by then-owner Peter Wheeler
, he reportedly concluded that the vehicle was too powerful to be practical and the project was scrapped.
V12 engine
A V12 engine is a V engine with 12 cylinders mounted on the crankcase in two banks of six cylinders, usually but not always at a 60° angle to each other, with all 12 pistons driving a common crankshaft....
manufactured by TVR
TVR
thumb|right|240px|TVR No.2, the oldest surviving TVR, located at [[Lakeland Motor Museum, Newby Bridge, Cumbria]]TVR was an independent British manufacturer of sports cars. Until 2006 it was based in the English seaside town of Blackpool, Lancashire, but has since split up into several smaller...
for use in the TVR Speed 12 race car, and later the TVR Cerbera Speed Twelve road car in which on the Cerbera Speed 12 went into production.
The engine was developed by essentially joining two Speed Six
TVR Speed Six engine
The TVR Speed Six was the name of a normally aspirated straight-6 engine manufactured by TVR, and used in several of their cars including the TVR Tuscan, TVR Cerbera, TVR Tamora, TVR T350 and TVR Sagaris....
engine blocks to a common crankshaft. The completed engine displaced 7.7 liters and was originally developed for racing applications in TVR's Speed Twelve. Later on, a version was developed for the prototype of a road car to be called the Cerbera Speed Twelve.
Unusually for an automobile, the Speed Twelve's engine block was not constructed of cast iron
Cast iron
Cast iron is derived from pig iron, and while it usually refers to gray iron, it also identifies a large group of ferrous alloys which solidify with a eutectic. The color of a fractured surface can be used to identify an alloy. White cast iron is named after its white surface when fractured, due...
or aluminum alloy
Alloy
An alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...
, but rather of steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
.
The racing version of the engine produced approximately 675 bhp with its power limited by the intake restrictors required by racing regulations. For the road-version of the engine, the restrictors were not needed so the engine was developed without them. According to reports from TVR engineers, the de-restricted engine snapped the central shaft of their 1000 bhp-rated dynamometer
Dynamometer
A dynamometer or "dyno" for short, is a device for measuring force, moment of force , or power. For example, the power produced by an engine, motor or other rotating prime mover can be calculated by simultaneously measuring torque and rotational speed .A dynamometer can also be used to determine...
during the bench-test. The engine's output was later estimated (conservatively) at 940 bhp. When the prototype vehicle was road-tested by then-owner Peter Wheeler
Peter Wheeler (TVR)
Peter Robert Wheeler was a chemical engineer from Sheffield, Yorkshire, UK, who owned the Blackpool-based TVR sports car company for 23 years....
, he reportedly concluded that the vehicle was too powerful to be practical and the project was scrapped.