Альфа Ромео Твин Камы: Тарихы мен эволюциясы

The Alfa Romeo Twin Cam engine is an all alloy inline four engine series produced by Alfa Romeo from 1954 to 1994. In Italian it is known as the "bialbero" ("twin shaft"), and has also been nicknamed the "Nord" (North) engine in reference to its being built in Portello, Milan (later Arese, close to Milan), in the North of Italy and to distinguish it from the Alfa Romeo Boxer engine built in the South (Sud) for the Alfasud.

Alfa Romeo's Autodelta competition arm produced a multiplicity of variations on the Twin Cam for different racing classes and cars including the racing oriented GTA. Displacements ranged from a over square version with a bore and stroke of up to a version with a bore and stroke of Many of these engines used dual ignition systems (see "Twin Spark"). Even though Alfa Romeo never sold a production version of the Twin Cam with more than 8 valves, at least two 16 valve cylinder heads were available. A number of Autodelta engines had them, and another 16 valve head was developed by the tuner Franco Angelini. Some Autodelta cylinder heads had an included angle between the intake and exhaust valves narrower than the 80° used in the majority of the production engines. These heads are called "testa stretta" (narrow head). Some engines also had what was called a "monosleeve" liner, where all four cylinder bore liners are cast side by side in a single piece. The 1959 Asardo 1500 AR S was a one off non Alfa prototype that used a custom built version of the Twin Cam. Starting with a block the bore was increased to by using custom pistons and wet liners from Mahle so that its final displacement was and power was .

In 1967 the Alfa Romeo GTA SA debuted at the Geneva Motor Show. Built by Autodelta, the Twin Cam engine was boosted by two superchargers driven by an engine powered oil pump. Power was reported to be
In 1979 the Alfa Romeo GTV Turbodelta was released. The 2 litre engine was augmented by a KKK turbocharger blowing through a pair of Dell'Orto DHLA40H pressurised carburetors and produced in normal tune. This car was only offered until 1981 when Alfa Romeo left Group 4 to concentrate on Formula 1. 400 were built. In 1984 Alfa released the Giulietta Turbodelta. Equipped with a Twin Cam, dual carburetors and an Alfa Avio turbocharger the engine produced
In 1986, a turbocharged version of the single plug engine developing was used to create the Alfa Romeo 75 1.8 Turbo Quadrifoglio. In Group A touring car racing form this engine made up to .

Alfa Romeo's Twin Spark technology used dual ignition to fire two spark plugs in the cylinder head of each piston bore and was first used in the A. L. F. A. Grand Prix car of 1914. Racing versions of the Giulia engine, including the engine used in the GTA, featured a cylinder head with two spark plugs per cylinder. Twin Spark versions of the Twin Cam were also developed for 1750 and 2000 models used for racing. In 1987 the production Alfa 75 2.0 Twin Spark was fitted with a Twin Spark head, which provided improved fuel ignition and allowed an improved combustion chamber shape with narrower angle between intake and exhaust valve. Although developed from the Twin Cam, few if any parts are interchangeable between Twin Spark engines and Twin Cams. For instance, while Twin Cams have six oilways leading to the cylinder head the Twin Sparks only have two, the timing chain cover is narrowed and the included angle between the valves is down to 46°. The Twin Spark engine in the 75 also employed Alfa's variatore di fase VVT system which, when combined with electronic fuel injection, gave a power output of
The last examples of the Alfa Twin Cam were the , and 8V Twin Spark engines featured in the 155 and 164. After 1995 the 155 featured the 16 valve Twin Spark which, although sharing features with the previous engine, is a different design that is a member of Fiat's "Pratola Serra" engine series, while the 164 continued with the 8 valve Twin Spark until the end of production in 1997. The production of the Alfa Romeo Twin Cam ended in 1997, by which time it had been gradually replaced since 1995 by the newer Fiat based 16 valve Twin Spark engines.