Twin Spark
| Alfa Romeo TwinSpark engine | |
|---|---|
| Overview | |
| Manufacturer | Alfa Romeo |
| Production | 1986–2009 |
| Combustion chamber | |
| Configuration | DOHC 2/4-valve I4 |
| Displacement | 1.4 L 1.6 L 1.7 L 1.8 L 2.0 L |
| Cylinder block alloy | aluminium alloy and cast-iron |
| Cylinder head alloy | aluminium alloy |
| Output | |
| Power output | 76 kW (103 PS) - 114 kW (155 PS) |
| Chronology | |
| Predecessor | Alfa Romeo Twin Cam |
| Successor | Alfa Romeo JTS engine |
Alfa Romeo Twin Spark (TS) technology was used for the first time in the Alfa Romeo Grand Prix car in 1914. In the early 1960s it was used in their race cars (GTA, TZ) to enable it to achieve a higher power output from its engines. And in the early and middle 1980s, Alfa Romeo incorporated this technology into their road cars to enhance their performance and to comply with stricter emission controls.
In the current Alfa Romeo world the "Twin Spark" name usually refers to the dual ignition engines installed in Alfa Romeo cars. The 8-valve engine was fitted initially to the Alfa Romeo 75 but also the Alfa Romeo 164 and Alfa Romeo 155. The 16-valve engines appeared in the Alfa Romeo 145, Alfa Romeo 146, Alfa Romeo 155, Alfa Romeo 156, Alfa Romeo 147, Alfa Romeo 166, Alfa Romeo GTV & Spider and even Alfa Romeo GT models.
The TS series engines are all '4-cylinder inline' with twin cam (DOHC) shafts. The original 8-valve engine was derived from Alfa's Twin Cam family, and featured a light alloy (Si enhanced aluminium alloy) block + head, wet-cooled iron cylinder liners, and the camshafts were driven by single double row timing chain. So, similar design to the earlier and famous Alfa Romeo Twin Cam engines, but with narrower valve angle and double ignition on this model.
The later 16-valve engines were part of FIAT's "Pratola Serra" (B family) modular engine series, and had a heavier cast-iron block engine, with an alloy head, and the camshafts were belt driven. The Twin Spark name comes from the fact that there are two spark plugs per cylinder. It was cast iron for its higher beam strength, less complexity and hence lower production costs. When new, these engines were notable for their high efficiency as demonstrated by the BMEP (brake mean effective pressures) exerted upon the piston crowns.
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Wikipedia