2.2 185 bhp JTS

The 4-cylinder engines fitted to the Alfa Spider are extremely light because they have aluminium cylinder heads and crankcases (they are approximately 20% lighter than the engines they replace). The timing gear control is also particularly advanced, featuring a system of rocker arms and rollers, which significantly reduces dispersion due to friction in the cylinder head, and the 'Twin Phaser' continuous variable valve timing system on the intake and exhaust valves, which optimises power output, torque and fuel consumption.

In detail, the 2.2 JTS delivers 136 kW (185 bhp) and peak torque of 230 Nm (23.4 kgm) at 4,500 rpm, taking the car to a top speed of 217 km/h and accelerating from 0 to 100 km/h in 8.8 seconds


Main technical features

To start with, the Twin Phaser system adopts new cam lobes which allow the phase angle to be varied by 50 degrees on both axes. This makes it possible to improve performance on the one hand because the best phase can be chosen at all engine speeds, and to reduce consumption and emissions with partial loads, by the Miller cycle. This combustion system, which is based on the postponed opening and closing of the inlet and exhaust valves - extends the expansive phase (converting more heat into energy), guarantees internal EGR (by preventing the release of the last exhaust gases, full of unburned particles) and postpones the closure of the inlet valve (reducing pumping losses).

Another peculiar feature of the 2.2 JTS engines that equip the Alfa Spider is the chain-driven camshaft system: unlike a conventional belt drive, this system has the advantage of not needing to be replaced during the lifespan of the engine.

And to guarantee the performance one expects of an Alfa Romeo, the timing curve has also been reviewed, adopting larger profiles which made it possible to achieve a maximum power output of 6500 rpm (the system is fine tuned to operate at over 7,000 rpm, the maximum rev speed allowed by the electronic speed limiter).

And more. To achieve the best volumetric efficiency, the maximum lift reaches 10.3 mm, while to enhance vibrational and acoustic comfort, the engine is equipped with two counter-rotating balancer shafts which virtually eliminate the second degree alternate forces that are typical of straight-4 engines. The generous power delivery of the engine (80 bhp/l on the 2.2 JTS) made it necessary to adopt sodium-cooled exhaust valves.

The combustion chamber is shaped like a roof with four valves per cylinder: with a bore of 86 mm, the large inlet valves measure 35.3 mm and the exhaust valves 30.3 mm, guaranteeing excellent permeability to enhance engine performance. And, in spite of the stroke of 94.6 mm, in order to limit the overall height of the engine, the engineers have modified the piston height, achieving a compression value of just 28 mm, which is excellent in view of the high power delivery.

Where the exhaust, injection and ignition systems are concerned, the two 4-cylinder JTS engines both adopt the strategies and features illustrated for the new 3.2 V6 Q4 engine.


'Spider is Alfa Romeo'

The four words 'Spider is Alfa Romeo', an advertising slogan in use nearly 30 years ago, neatly sum up eighty years of Alfa Romeo spider convertible production (in both technical and emotional terms). An automotive manufacturer such as Alfa Romeo whose name has always been a byword for motorsport, can only give free rein to its idea of freedom and passion by building a convertible.

Like many historical icons that have passed into the common consciousness over the course of the decades, the Alfa Romeo convertible was created without a specific name to identify it. The period was the beginning of the twentieth century, spoked-wheeled cars created in Portello, such as the 40-60 HP, the 20-30 ES, up to the RL (Alfa Romeo's first creations) were put through their paces against the chequered flag over circuits such as Targa Florio, Brescia, Modena and Parma. The management of the day were quick to realise that they could never come up with a better advertising slogan than that of offering customers a car that could boast such a wealth of sporting accolades.

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