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A V8 engine is a V engine with eight cylinders. The V8 is a very common configuration for large automobile engines. V8 engines are rarely less than 3 litres in displacement and in automobile use have gone up to 8.5 litres or so. American cars until the mid 1970s almost universally had V8 engines, and many still insist on them.

The normal V-angle for a V8 is 90. There are two classic types of V8s which differ by crankshaft.

The cross-plane V8 is the typical V8 configuration used in American road cars. Each crank pin (of four) is at a 90 angle from the previous, so that viewed from the end the crankshaft forms a cross. The cross-plane can achieve very good balance but requires heavy counterweights on the crankshaft. This makes the cross-plane V8 a slow-revving engine that cannot speed up or slow down very quickly compared to other designs, because of the greater rotating mass.

The flat-plane V8 design has crank pins at 180. They are imperfectly balanced and thus produce severe vibrations. As they don't require counterweights, the crankshaft has less mass and thus inertia, allowing higher RPM and quicker acceleration. They're mainly used as racing engines, the most famous example being the Ford-Cosworth DFV.

The Coventry-Climax 1.5 litre V8 evolved from a cross-plane configuration to a flat-plane configuration in its latest versions.

American V8 Engines

The United States can be considered the 'home of the V8' - it has always been more popular there than anywhere else, and it is certainly even now the preferred arrangement for any large engine. With the recent exceptions of the Dodge Viper's V10 and the Ford large truck engine of the same arrangement, there are practically no large engines in the US of post-World War II design that have not been of this type.

Ford were the first company to use V8s en masse - instead of going to a six-cylinder engine like its competitors when something larger than a straight-4 was needed, Ford went straight to the V8 with its famous Ford Flathead V8 of 1932. This engine powered almost all larger Ford cars until 1953, and was produced until around 1970 by Ford licensees around the world, mostly powering commercial vehicles.

Some other companies followed Ford and built V8s, while others, like Buick, used straight-8 engines for their larger cars, and straight-6 engines for smaller ones. Postwar, increasing vehicle size meant that the straight-6 became increasingly underpowered, while the straight-8 was simply too long. This meant that by the 1950s, all American automobile manufacturers had a V8 in their range, powering the majority of the vehicles sold.

A full history of each manufacturer's engines is out of scope in this article, but engine sizes on full-size cars grew throughout the 1950s, 1960s and into the early to mid 1970s. The increasing size of full-size cars meant that smaller models of car were introduced and became more popular, with the result that by the 1960s most manufacturers had two V8 models.

The larger engines, known as big-block V8s, were used in the full-size cars. Big-blocks generally had displacements in excess of 6 litres (360 cubic inches), but in stock form are often not all that efficient. Big-blocks reached displacements of up to 8.2 litres (500 cubic inches) in production form. Once the 1970s oil crisis and pollution regulations hit, big-block V8s didn't last too much longer in cars; luxury cars lasted the longest, but by 1977 or so they were gone. In trucks and other larger vehicles, big-block V8s in their historic form lasted until the early 1990s.

Smaller engines, known as small-block V8s, were fitted in the mid-size car ranges and generally displaced between 4.4 litres (270 cubic inches) and 6 litres (360 cubic inches), though some grew as large as 6.6 litres (400 cubic inches). As can be seen, there is overlap between big-block and small-block ranges, and an engine between 6 and 6.6 litres could belong to either class. Engines like this (much evolved, of course) are still in production.

British V8 engines

The most common British V8 is the Rover V8, used in countless British performance cars. This is not actually a British design at all but was imported from America, its roots being in General Motors development of a cast-aluminum block small V8 in the late 1950s. This engine was of the small (for the US market) size of 3.5 litres (215 cubic inches). It appeared in production in 1961 on some of that year's Buick, Oldsmobile and Pontiac models, but was soon dropped in favor of more conventional iron-blocked units.

Rover were in need of a new, more powerful engine in the mid 1960s, and became aware of this small, lightweight V8. After some negotiation they acquired rights to it and have produced it ever since, its first appearances being in Rover saloons in the late 1960s.

As well as appearing in Rover cars, the engine was widely sold to small car builders, and has appeared in all kinds of vehicles. Rover V8s feature in some models from Morgan, TVR , Triumph and MG, among many others. They're also the standard British engine in hot rods, much like the Chevrolet 350 small-block is to American builders.

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V8 is also a beverage made of juices from 8 vegetables, specifically: tomatoes, beets, celery, carrots, lettuce, parsley, watercress, and spinach.