A VERY COMPREHENSIVE ARRAY OF SOPHISTICATED ENGINES AND GEARBOXES
 

Behind the strong personality of its styling, the Grande Punto offers a comprehensive range of excellent engines featuring advanced technology and generous performance. There are two petrol engines (1.2 8v delivering 65 bhp and the 1.4 8v delivering 77 bhp) and four Multijet turbodiesel units: the 75 bhp or 90 bhp 1.3 16v, and the 120 bhp or 130 bhp 1.9 8v. Each has different features which are exploited in full in combination with 5 or 6 speed mechanical gearboxes, which stand out for their generosity, sparkling character, high performance and sophisticated technology. The features they share are outstanding reliability and respect for the environment: all the engines respect Euro 4 emissions limits.

All the Grande Punto engines are built by Fiat Powertrain Technologies, the Group's new operating sector. FPT groups together all Fiat Auto's activities in the fields of innovation, research, planning and production of engines and gearboxes for all types of application, from cars to commercial vehicles, boats and agricultural machinery. More than 3000 work in the FPT research centres in eight different countries and they help to make this sector a great centre of technological excellence and constant innovation.

Diesel engines: the history of Fiat's achievements

The 75 bhp and 90 bhp 1.3 16v Multijet

The Fiat Punto could not fail to mount the 1.3 16v Multijet - the smallest and most advanced second generation direct injection Common rail diesel engine - now with an important novelty: a new version with a variable geometry turbo is making its debut. With this turboboost system, the 1.3 16v Multijet delivers a power output of 90 bhp (66 kW at 4000 rpm) and peak torque of 20.4 kgm (200 Nm at 1750 rpm). That is not all. With the 90 bhp 1.3 Multijet, the Grande Punto achieves outstanding performance: it has a top speed of 175 km/h and accelerates from 0 to 100 km/h in just 11.9 seconds. Even consumption is among the lowest in this segment: 5.9 l/100 km in the urban cycle, 3.9 l/100 km out of town and 4.6 l/100 km in the mixed cycle.

The new engine differs not only for the different turboboost system (on the 75 bhp 1.3 Multijet it is provided by a fixed geometry turboblower), but also for other changes. The combustion system has been modified, increasing the permeability of the inlet and exhaust manifolds, reducing turbulence in the combustion chamber and varying the geometry and the compression ratio from 18:1 to 17.6:1. The emissions control system envisages an EGR valve with electric actuation managed directly by the engine control system, a heat exchanger to cool the recirculating exhaust gas (EGR), and a 'close coupled' catalytic converter, which guarantees respect for EC Phase 4 emissions limits.

The performance of the 1.3 Multijet is also excellent; it delivers a power output of 75 bhp (55 kW at 4000 rpm) and peak torque of 19.4 kgm (190 Nm at 1750 rpm). With this engine the Grande Punto has a top speed of 165 km/h and accelerates from 0 to 100 km/h in 13.6 seconds, with excellent combustion: 5.9 l/100 km in the urban cycle, 4.0 l/100 km out of town and 4.7 l/100 km in the mixed cycle.
 
These are the differences between the 75 bhp and the 90 bhp versions. On the other hand they both share the engine architecture: 4 cylinders in line, 1248 cc, with a bore of 69.6 mm and a 'long' stroke of 82 mm. There are four valves per cylinder, driven directly by twin overhead camshafts via rocker fingers with a roller. That is not all. The 1.3 Multijet 16v is a masterpiece of technology in miniature: complete with all its accessories, it weighs just 130 kg, and is also small in size, just 50 centimetres long and 65 centimetres high, with the components laid out to take up as little space as possible.
Designed to criteria of maximum rationality, efficiency and reliability, the engine is capable of excellent performance, and is practically built 'for life': it was designed to travel 250,000 km without any maintenance to the mechanical components. What is more, the oil change intervals have been extended from 20,000 to 30,000 km (the 1.3 Multijet 16v uses low viscosity oil, which means more fuel economy, and it respects the environment). This compact, technologically sophisticated engine is also environment-friendly, because it meets Euro 4 emissions limits even without a particulate trap, which is available on request for certain markets.

The 1.3 Multijet 16v (whether 75 or 90 bhp) therefore represents a real leap forward in technological terms, and this translates into lower fuel consumption and emissions for the customer. Without even considering the increased quietness (due to the multiple injections), the enhanced comfort (fewer alternating masses mean less vibration), the smoothness and enjoyment of driving it (due to the extremely smooth torque delivery, that comes from better control over combustion), elasticity and the prompt response of a diesel unit which resembles a petrol engine because of the vast rev range (for example, the driver is no longer aware of the 'fuel cut-out' just above 4000 rpm), the environment-friendly features that enhance the diesel's great quality on the environmental front (consumption) and keep its main defect (particulate emissions) to a minimum.

The 120 bhp and 130 bhp 1.9 Multijet

Both engines have 4 cylinders in line, and two valves per cylinder, with a bore of 82 mm and stroke of 90.4 mm. The first delivers 120 bhp (88 kW) at 4000 rpm and torque of 28.5 kgm (280 Nm) at 2000 rpm; the second delivers 130 bhp (96 kW) at 4000 rpm and torque of 28.5 kgm (280 Nm) at 2000 rpm. Several changes were made to the two engines to increase performance and engine torque at low speeds, and to reduce noise and vibration. For example, the "Common Rail" system envisages two automatic control strategies for the setting and balance of the injected diesel fuel, which reduces noise and vibration. The turboboost is provided by a variable geometry Garrett VGT 17 turboblower with electronic control that helps to improve the power delivery, but also generates very high torque at low engine speeds. In fact, 90% of peak torque is available between 1750 and 3250 rpm. These figures translate into extremely enjoyable driving and brilliant performance: powered by the 120 bhp 1.9 Multijet engine, the Grande Punto Emotion has a top speed of 190 km/h and accelerates from 0 to 100 km/h in 10 seconds (the values for the Sport version with the 130 bhp 1.9 Multijet engine are 200 km/h and 9.5 seconds). Brilliant performance, but in spite of this, fuel consumption remains low: 7.5 l/100 km in the urban cycle, 4.5 out of town, and 5.6 in town (the values for the 130 bhp 1.9 Multijet are 7.6, 4.6 and 5.7).

Last but not least, both the 1.3 Multijet and the 1.9 Multijet mounted on the Grande Punto respect Euro 4 legislation and offer a particulate trap (DPF), a 'for life' system that eliminates fine dust and does not need additives to regenerate it.

The Multijet system on the second generation JTD engines

The Multijet turbodiesel engines mounted on the Grande Punto are jewels of modern engineering which confirm Fiat Auto's leadership in this field. When it developed the Multijet system, the Fiat Group set an important new record in the field of diesel engines, made possible by the huge amount of expertise accumulated since 1986, when the Croma TDI was launched, the world's first direct injection diesel-engined car. For those years it was a brilliant result, the first important step forward towards more efficient combustion in the field of diesel engines for cars. Thanks to this technology, which other manufacturers soon adopted, diesel-engined cars were able to guarantee both better performance and lower consumption. One problem remained: the excessive noise made by the engine at low speeds and in 'speed transients'. This is where the history of the Unijet starts, or rather the search for a more evolved direct injection system, which could drastically reduce the problem of noisy combustion. After a few years, this research produced the Unijet, but it also brought other advantages in terms of performance and consumption. There were only two possible ways of solving the problem: passive acceptance, isolating the engine to prevent the sound waves from spreading, or working actively to eliminate the problem at source, developing an injection system that could reduce combustion noise. Having chosen the second strategy, the Fiat engineers immediately concentrated their research on the 'Common Rail' principle, excluding other high pressure injection systems after careful analysis. The other systems did not allow the pressure to be managed independently of the rpm and the engine load, nor did they envisage pre-injection, the two strengths of the Unijet. The theory that the engineers started to analyse was both simple and ingenious, the fruit of work done by researchers at Zurich University, which had never been applied on a car. By continuing to push diesel fuel into a tank, pressure builds up inside the tank, which thus becomes a hydraulic accumulator, or 'rail', in other words a reserve of pressurised fuel, ready to use.

Pre-industrialisation of the Unijet, the system developed by Magneti Marelli, Centro Ricerche Fiat and Elasis on the basis of the Common Rail principle, began three years later, in 1990. This stage was concluded in 1994, when Fiat Auto decided to choose a partner with great experience in the field of injection systems for diesel engines. The project was therefore sold to Robert Bosch for the final part of the work, i.e. completion of the development process and industrialisation. In October 1997, eleven years after the Croma TDI, another record-setting car went on the market: the Alfa 156 JTD equipped with a revolutionary turbodiesel engine that gave hitherto unimaginable results. The cars equipped with this engine were incredible quiet, with a sparkling response on a par with that of a petrol engine and performance levels that were 12% higher than those of a similar pre-combustion engine, as well as 15% lower consumption. The success of the Alfa 156 with the JTD engine was immediate, and very soon not only was it being used on other Fiat Auto models, but numerous other car-makers were adopting similar engines. Now it is the turn of the second generation of JTD engines, the Multijet multivalve units.

The underlying principles of second generation turbodiesel engines remain those of the Common Rail, i.e. high injection pressure and electronic injector control. But one extra feature has been added: during each engine cycle, the number of injections increases over and above the current number of two. In this way, the same amount of diesel is burnt inside the cylinder but in several portions to achieve smoother combustion. The advantages include lower running noise, reduced emissions and a 6-7% increase in performance. All this comes with a level of engine efficiency that improves car handling still further. These results are not to be underestimated, particularly because they are obtained with an engine that represents an incredible leap forward from pre-chamber diesels and even improves on first generation JTD engines.

The secret of the Multijet engine lies in the control unit that governs the electric injector opening and closure system (and also in the injectors themselves). The crucial element is the electronic control unit itself that can perform a set of injections that may be very closely spaced.

Fiat Auto's researchers developed the part (together with the injectors) especially for this application. It is designed to deliver the multiple injections that assure more accurate control of pressures and temperatures developed inside the combustion chamber and also more efficient use of air taken into the cylinders. This enables further goals to be achieved: quieter combustion, reduced emissions and increased performance.
 
The Multijet system is underpinned by long years of research. Our engineers began by resolving the problem of the limits imposed by the control units. Then they went on to map the benefits they could achieve by plotting different multiple injection sequences (two secondary injections very close to the main injection; one secondary injection not too close to the main injection plus two closely-spaced secondary injections; one secondary injection and then two main injections close together after a certain period, etc.) against different engine service conditions: in the idling region; with low loads and low rpm; with high rpm and moderate load; with low rpm and high load, etc..

The study revealed the potential of the system and showed that great benefits are achievable in all cases, though these tend to focus on one field or another according to the type of sequence chosen and the engine service area targeted. In some cases, for example, the priority is to reduce start-up times and fume levels, in other cases it is to increase torque and reduce noise while in others still it is to reduce emissions and ensure a quieter drive. And now this research strand has led to the creation of the Multijet engines, including the brand new 90 bhp 1.3 JTD Multijet 16v which debuts on the Grande Punto.
 

The novelties in the Fire family

The 65 bhp 1.2 Fire 8v

The tried and tested 1242 cc Fire engine makes its debut on the Fiat Punto with a number of refinements designed to make it a champion of thriftiness where consumption is concerned, but without detracting from performance. The engine delivers 48 kW (65 bhp) at 5500 rpm and takes the car to a top speed of 155 km/h.

That is not all. With the 1.2 8v engine, the new car has very low fuel consumption, among the best in its category. The merit goes to the engine configuration, which aims to achieve generous torque at very low revs (with benefits in terms of enjoyment and elasticity), and to the ratios chosen to optimise the balance between performance and consumption. The result is torque of 10.4 kgm (102 Nm) at 3000 rpm and consumption of 7.9 l/100 km (urban cycle), 5.1 l/100 km (out of town) and 6.1 l/100 (combined cycle). Interesting results which were achieved with a few effective improvements. For example, new inlet and exhaust manifolds, a new combustion chamber (with the compression ratio now 11:1), and new cam profiles to optimise the fluid dynamics of the engine, thus improving efficiency.

Also with the target of reducing consumption, the engineers chose an active knock sensor, capable of managing the advance efficiently in all conditions and, above all, the Marelli phased sequential multipoint injection system, which was only available on more sophisticated engines until a short time ago. The new model adopts a 'drive by wire' system which eliminates the mechanical link between the accelerator pedal and the throttle valve, significantly improving the torque delivery on the basis of the driver's demands, translating it into benefits for the customer in terms of driveability and consumption.

Where performance is concerned, we should underline the use of an electronic control system developed for the car and based on a new generation Marelli electronic control unit, capable of dialoguing in a network with the electronic devices on the car through serial lines. The quality of life on board also improves as a result of the optimised performance of the inlet and exhaust systems, the optimisation of the coupling tolerance between the crankshaft and the crankcase, the computerised selection of the main bearings, and the development of a specific method to install the engine in the engine bay. This also reduced the amount of vibration transferred from the engine to the bodyshell. A special barycentre system was adopted to support the engine, with two blocks plus a reaction link that acts as a tie rod, with the result that the new supports are aligned on an axis that passes through the engine's centre of gravity, to obtain reaction forces with a neutral link.

An efficient engine, and a clean engine. Where the environment is concerned, the 1.2 8v respects EC phase 4 anti-pollution standards, thanks to the new AISI steel exhaust manifold with a catalytic converter in the engine bay, welded on the flange of the exhaust manifold. The device is very efficient in this position, because it can reach high temperatures more rapidly, reducing emissions while the engine is still heating up. The equipment present on the Grande Punto 1.2 8v to reduce its environmental impact includes a returnless fuel supply system, which eliminates the recirculation of fuel inside the tank and reduces the formation of fumes.

And finally, to improve reliability the coils have been mounted close together in a single block. This new type of coil reduces shock absorber wear, making more energy available to ignite individual spark plugs because the lost spark has been eliminated, easier cold starts because more energy is available for the spark plug (more energy supplied by the coil and no losses during the high voltage transfers because very short cables are used) and, finally, a significantly reduced risk of interference to the onboard equipment from high voltage cables.

The 77 bhp 1.4 Fire 8v

The new engine has a capacity of 1368 cc and four cylinders in line, with a bore of 72 mm and a stroke of 84 mm. There are two valves per cylinder, activated directly by the overhead camshaft. The engine was developed paying particular attention to performance and consumption, areas in which the Fiat Punto leads its category. This is achieved as a result of the volumetric efficiency, which has been optimised throughout the operating range, thanks to careful fluid dynamic development of the entire inlet system and the timing. The result is a power output of 57 kW (77 bhp) at 6000 rpm and a peak torque of 11.7 kgm (115 Nm) at 3000 rpm. With this engine, the Fiat Punto has a top speed of 165 km/h, and accelerates from 0 to 100 km/h in 13.2 seconds. Consumption figures are among the best in this segment: 7.7 l/100 km in the urban cycle, 5.2 l/100 km out of town, and 6.1 l/100 km in the mixed cycle.

An engine that is both brilliant and sparing on fuel. This performance is helped by the adoption of an electronic throttle valve control system known as 'drive by wire', and in particular by the use of a new high turbulence combustion chamber which is combined with continuous variable valve timing, governed by the control unit. This innovative system allows a significant part (about 25%) of the exhaust gases to be recirculated in the combustion chamber, significantly reducing fuel consumption and exhaust emissions when driving with a partial load. Last but not least, like the 1.2 8v, this engine also features a number of changes designed to reduce consumption. For example, the timing components are lighter and the valve springs are of the low load type to reduce friction.

Another feature of the new 77 bhp 1.4 is the higher compression ratio (11:1) and the high torque delivery at low speeds, features that have made it possible to lower fuel consumption. This target was also achieved by the calibration of the latest generation engine control system, which managed to reduce consumption further, compatibly with the demand for handling, performance and low emissions. In the latter field, we should underline that the 77 bhp 1.4 Fire engine also respects Euro 4 standards, thanks to a catalytic converter positioned in the engine bay (welded onto the exhaust manifold flange using a new technology), and it reaches a high temperature very rapidly, cutting emissions even while the engine is heating up. The equipment on the new car to reduce its environmental impact includes a returnless fuel supply system, which eliminates the recirculation of fuel inside the tank and reduces the formation of fumes.

High performance, low consumption and cleanliness: the 77 bhp 1.4 combines these winning features with excellent acoustic comfort. In addition to the technical improvements described for the 1.2 Fire engine, this engine also features a flexible flywheel that reduces the vibration transmitted from the engine to the bodyshell.

Reliable, sophisticated gearboxes

A range of reliable, strong, sophisticated gearboxes was developed to match the engines available on the Grande Punto, and these components are an important aspect of enjoyment and comfort (robotised Dualogic gearboxes will also be available after the launch).

A new dual hose control was developed for all the gearboxes, to insulate vibration, guaranteeing more precise manoeuvring and quieter operation. It is a new generation, technologically advanced device, which uses high performance technopolymers extensively, on the basis of the different resistance, weight and self-lubricating characteristics. Plus the fact that bench testing in extreme climate conditions has helped to refine materials, couplings and processes, guaranteeing the utmost sturdiness and reliability of the product. What is more, the quality and reliability of these components is guaranteed by the painstaking care that goes into their assembly, during which all the components are pre-tested and all the 'values' that define efficiency, elasticity and tolerances are measured electronically.

All versions adopt the hydraulic clutch disengagement control, with an external actuator on the 1.2 and 1.4 Fire and 1.3 Multijet engines, and a coaxial clutch release mechanism (CSC) on the 1.9 Multijet. The device, which has no external actuation components, increases the efficiency of the system throughout the life of the car and also insulates the noise and vibration coming from the engine. Compared to a hose control, the hydraulic control guarantees automatic adjustment of pedal wear; on the JTD versions, this system is combined with a device that takes up the clutch plate wear so that the load of the clutch pedal remains constant for the car's entire life. To comply with European legislation to protect the environment, all versions, both petrol and diesel, adopt friction materials that only contain environment-friendly elements. And the clutch pump has a plastic body, which helps to lower the weight, a steel cylinder and a plastic piston.

The 5-speed gearbox for the 1.2 8v and 1.4 8v engines

Enhanced acoustic comfort, reduced engagement effort even when cold, and more precise gear engagement. These are the advantages of the C514 gearbox (a transverse configuration with two shafts in a cascade and one differential), which was optimised by changes to: the gears, synchronisers, lubrication, internal gear control and clutch control. Combined with the 5-speed Fire 1.2 8v and 1.4 8v engines, this version represents the maximum upgrade of the gearbox in terms of transmissible torque (15 kgm). The use of nobler materials for the gears, the adoption of a more powerful differential with larger conical gears and the screw connection between the housing and the crown all improve reliability. The main features are excellent manoeuvring of the gear lever, quiet operation and low weight.

What is more, the gearbox adopts a gear control which, thanks to stroke limiter selection, protects against the risk of involuntarily engaging reverse, and makes engagement of fifth and sixth speeds more precise. And finally, the use of gearing made of quality materials and of a completely redesigned differential, made it possible to strengthen the gearbox itself, which in this configuration can transmit up to 15 kgm of torque.

The most significant technical features are the gearing and clutch housings, which were optimised to lower the weight and to absorb noise better, using FEM (Finite Element Method) calculation techniques. Plus Borg-Warner free-ring synchronisation on all gears. And finally, a dual cone synchroniser on first and second, the gears used most frequently, with an engagement effort that is 40% lower than the effort required with a conventional single cone synchroniser.

The internal gear control system has four selection levels, with a central positioner and bearings. Lubrication is dynamic, and the oil flow is channelled through bore holes in the housing. The advantages are less wear and more efficient torque transmission, and manoeuvrability even at low temperatures.

The 5-speed gearbox for the 75 bhp 1.3 Multijet engine
 
The C510 is extremely easy to manoeuvre and very quiet. It has a transverse configuration with two shafts in a cascade and one differential. In this case too, the gearbox has been optimised, adopting a dual cone synchroniser on first and second, and a highly efficient reverse engagement control. Two improvements that guarantee the product's excellence where manoeuvring is concerned. Lubrication is dynamic and the oil is channelled through bore holes in the housing and on the shafts. The maximum torque transmissible is 21 kgm.

The 6-speed gearbox for the 120 bhp and 130 bhp 1.9 Multijet engine and the 90 bhp 1.3 Multijet

The M20 and M32 gearboxes belong to a new family of three-axis transmissions, designed to give better manoeuvring and to be more compact than traditional two-axis gearboxes. Available with 6 speeds, these two units can support high torque (230 Nm and 320 Nm), so they are the ideal for high performance diesel engines: the 90 bhp 1.3 Multijet (M20) and the 120 bhp and 130 bhp 1.9 Multijet (M32).

In this case too, the engineers' goal was to improve acoustic comfort, to eliminate any vibration or shaking of the gearshift, and to reduce actuation and engagement effort even when the engine is cold. The gearbox (with three shafts and a built-in differential) has small axial measurements, and is easy to manoeuvre in all speeds, and extremely quiet. The credit goes to a number of innovative solutions that were already employed on earlier gearboxes, such as free ring synchronisers, dual-cone synchronisers on first and second, and dynamic lubrication.