Renault-Nissan Diesel Engine

Boosting Performance

Bertrandt France Helps to Develop Renault/Nissan’s Latest Diesel Engine
Renault’s current strategy includes developing innovative engine/transmission units that meet the Euro 4 standards. A particular highlight is the latest development in their engine range - the new 2.0 dCi diesel engine, in which developing Bertrandt France was involved in.

 

Challenge: Developing the most powerful diesel engine while complying with all environmental regulations
Renault was in charge of designing the new diesel engine. The new power unit competes with the best performing engines on the market. Ever since the start of this demanding project in September 2002, Bertrandt was involved in developing the entire base engine above the cylinder head gasket, as well as the intake and exhaust systems and durability testing. Special attention was also paid to the wide-ranging production and environmental requirements.

Considering production requirements
Parallel to the development of the 2.0 dCi, a new assembly line was put into operation at the Cléon plant near Rouen. The contact persons supporting the process were involved in the development of the various components from the concept phase onwards. This allowed all the specific requirements to be taken into account at an early stage. Even during the design process, Bertrandt considered all the requirements at the plant, such as processes, service and vehicle and engine assembly, while at the same time keeping in close contact with the suppliers. The focus at all times was on the main objective: to secure a manufacturing process that meets Renault’s stringent quality standards.

Environmental requirements
The engine/transmission unit had to be adapted to the Euro 4 emissions standard. This was, of course, not to be at the expense of engine performance. The teams from Renault and Bertrandt optimised all components without revolutionising the entire engineering. As a result, power output, torque and fuel consumption were considerably improved. The 2.0 dCi therefore relies on proven technology - without multiple turbocharging or even increasingly highpressure fuel injection.

Design
For the area of the upper base engine and the intake system, Renault has chosen top-quality products in order to get the very best out of its new power unit. For example, it includes third-generation fuel injection from Bosch. This system works with six-hole piezo-electric injectors that allow four to five injections per cycle. At 3 000 rpm, it provides two pre-injections, the main injection and one post-injection. The two first injections heat up the combustion chamber. This promotes rapid ignition of the main injection, thus reducing noise and at the same time optimising pollutant emissions. The post-injection allows an almost total post-combustion of the soot content. The remaining soot is collected by the particulate filter and removed by periodic regeneration. In addition to the improvements in fuel injection, the compression ratio was reduced to 15.7:1, as is the case with all new ramp injection engines of the third generation. This serves to limit the combustion temperature and the NOx emissions. Furthermore, Bertrandt successfully worked on adapting the air intake, which is also vitally important for the performance of the engine.

Computation
Computation played a major role during the entire course of the project. Bertrandt was responsible for the computation of all assemblies - fuel injection system, air intake, etc. - and designed the exhaust gas recirculation system (piping and valve) together with the Renault team. In the area of the exhaust system, computations were also performed on the vibrations of the manifold, turbocharger and catalytic converter. At present, work is being carried out on the further development of the new version, in particular on components such as the crankcase, bearing cover and cylinder head. The focus is on taking into account the necessary modifications to the basic structure, particularly in relation to the new regulations on pedestrian safety, at an early stage..

Testing

The first tests on the engine test stand and subsequently in vehicles were used to verify the design and computations. This was followed by further observation and analysis of the weak points within the scope of several release cycles.

Bertrandt was responsible for numerous components within the engine validation process (intake, EGR, exhaust system). This involved not only the everyday project support but also the complete analysis of the parts after the tests as well as the development of suggestions for improvements to remove the sources of defects. This was done in close cooperation with the design teams and the suppliers.

Supplier management
The suppliers were integrated into the process of developing and building the engine. During the entire administration and technical documentation of the individual components, the teams from Bertrandt worked closely together with the suppliers. Regular meetings were organised with the purchasing departments reporting to Renault, in particular to determine coordination processes and final requirements as well as to clarify financial aspects. Coordination with the suppliers continued right up to the transfer of the project to series production.


Project management
Assignment of responsibility, process control, teamwork, communication
Within the scope of the cooperation with Renault, the 2.0 dCi is an example of a project in which Bertrandt was given comprehensive responsibility. In contrast to providing purely technical support, Bertrandt is in this case responsible for the complete project and its delivery - to the same extent as the Renault teams. The organisation is specified monthly by a steering committee. In this project, Bertrandt coordinated its processes with those of Renault in order to achieve optimum transparency and comparability throughout the entire project.


Project planning
Precise planning was required to ensure that the project ran smoothly and to define the activities of all those involved. All responsibilities with regard to design, technical requirements, parts availability and testing, both on the test stand and in the vehicle, were coordinated. The aim was to ensure that all project evaluations up to the final production release were successfully passed.


The 2.0 dCi and its future
The 2.0 dCi is being manufactured in Cléon. It will soon make up half of the production at the plant and will be installed in several models from Renault and Nissan. The highly motivated Bertrandt teams are currently facing up to new challenges and are working with great commitment on new applications for this engine. At present, 30 Bertrandt employees are working on the ongoing project either at Bertrandt in Bièvres and/or directly at Renault in Rueil Malmaison.


Conclusion: Performance booster
Over the past four years of joint development work, Bertrandt successfully mastered new technical challenges, taking on the role of a "performance booster". We would like to thank Renault for giving us the responsibility for the project and for the trust it has placed in us..