The modern Turbo Diesel engines have increased their performances  compared with “old” Diesel engines but recently they have to face new severe requirements regarding their emissions. The use of EGR (Exhaust Gas Recirculation) can help engine manufacturers to keep under control the emissions in order to accomplish to the Euro 4 requirements.

In order to improve EGR system VM Motori S.p.A. (Cento, FE – ITALY) decided to test different alternative INTAKE MANIFOLDS. It could take a long projecting and engineering time, but thanks to VM engineers’ good knowledge of RP techniques only few weeks were spent to reach the best performance of the manifold and the engine.

The study was performed using 3 different models, made by C.R.P. Technology in WINDFORM®XT, the latest carbon fibres filled material, for RP Laser Sintering systems.
Each prototype was prepared with a typical lead-time of 2/3 days. This kind of “fast-production” was very useful for VM engineers, shortening 10 times or more the standard lead-time for this kind of product.

With the first model “V1” they realized that it was possible to use the WINDFORM®XT INTAKE MANIFOLD without any problems for their dyno tests; then they worked on other two releases, “V2” and “V3”, in order to optimize the partitioning of EGR on each cylinder, reaching the goal of a maximum of 4% of difference among the 4 cylinders (as a target for Euro 4 emission level).

Usually “standard” lead-time for a sand cast aluminium intake manifold is about 2 months. In this case they made 3 different manifolds spending only 6/9 working days. So the engineering phase that usually takes several months, lasted less than 2 weeks!

In the following table we can see some interesting data to give  an idea about thermal and mechanical stress, applied to the Manifold, during normal engine use (real life engine operating points where the EGR is activated so the intake temperature is increased by mixing fresh air and hot exhaust gases).

VM engineers have done several tests, without any kind of problem. The manifold has supported also some tests lasting 2,5 hours, with the engine at the maximum output, and at the end, it was still perfect, ready to be used again.

For the production of this new Turbo Diesel Common Rail 2000 cc engine, engine designers decided to use aluminium manifolds and when they tested the first engines, they observed exactly the same results of WINDFORM®XT manifolds. It demonstrates how reliable and useful can be a study done in a incredible short time, thanks to WINDFORM®XT properties.

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