The long-lived family of Twin Spark 16v engines was snubbed by purists yet appreciated by a whole new generation of Alfisti, as it went on writing a long and successful chapter of Alfa history, under the bonnets of beloved modern classics like the GTV, the 156, and the 147.
Following its acquisition of Alfa Romeo in 1986, Fiat Auto found itself producing a remarkably varied selection of engines in the 1.5 to 2.0 liters range. Fiat-Lancia's legacy designs, like the "Lampredi" twin-cam four-cylinder, Alfa's own classic twin-cam and its Twin Spark derivatives, plus the "boxer" engines from the Naples factory.
Much to the Alfisti's dismay, such a wide variety of entirely different powertrains made in separate factories made little sense from an industrial point of view. Especially given the relatively low production volume of each of these engine families.
The decision to feature double ignition on the engines destined for Alfa Romeos was primarily taken for marketing reasons and then imposed on the engineers.
That's why Fiat Auto, in the early 90s, invested heavily in a new family of engines to replace them all. The modular design allowed a wide variety of four or five cylinders, petrol or diesel engines, to be made on the same highly automated production line.
The engine block, a thin-wall iron casting, could house two counter-rotating balancing shafts depending on the application. Most petrol engines' aluminum heads had four valves per cylinder and an electronically controlled variator on the intake camshaft.
The decision to feature double ignition on the engines destined for Alfa Romeos was primarily taken for marketing reasons and then imposed on the engineers.
Why?
Well, the management knew the public expected Alfa Romeo engines to be something special. The success of the Twin Spark engines had made the TS moniker almost synonymous with the brand, so they wanted to keep writing Twin Spark on the back of the cars. Putting two spark plugs into a four-valve cylinder head was a challenge, given the very little space available. This led to the peculiar solution of two plugs of different sizes placed side by side. These plugs were of very high quality, developed explicitly by NGK, to last a minimum of 100.000 km.
their time had already passed, as the advent of direct petrol injection made dual ignition not only redundant but physically impossible.
The new generation of Twin Spark engines debuted, just as it happened with the original TS in 1987, with the larger two liters variant, in 1995. And it certainly did it in style, with the sexy GTV and Spider designed by Pininfarina. The same unit became available on the 155 and the newly-introduced 145 Quadrifoglio Verde later the same year, and, by 1996, the smaller 1.6 and 1.8 16v engines came out to fully replace the older Twin Spark engines on the 155.
By 1997, with the demise of the boxer, the 145 and 146 also switched to the new Twin Spark engines. At the bottom of the range, a new 1.4 liters variant was introduced, a short-lived engine, though, lasting in production for only three years before being "sacrificed" on cost grounds.
With the launch of the 156, the 1.8 and 2.0 liters Twin Spark engines were uprated with an electronically controlled variable inlet manifold. Still, the big news of the time was the launch of the revolutionary common rail diesel engines. These would take the lion's share of 156 and 147 sales, thanks to their blend of high performance and low fuel consumption. The Twin Spark engines would get to live on until 2010 as the entry-level options for the 147 and GT models, even though their time had already passed, as the advent of direct petrol injection made dual ignition not only redundant but physically impossible.