The Conceptor of MCE-5 VCRiTechnology

Vianney RABHI is the inventor of MCE‑5 VCRi technology. He is self-taught in the field of engines. As a teenager, he spent most of his free time in his high school’s technical library, studying books on engines and thermodynamics. At 18, he built a garage on his parent’s farm and learned about the practical side of mechanics with the help of a retired professional. In 1985, he filed his first patents applied to internal combustion engines. His first concepts were without prospects but they were nevertheless an opportunity for him to start sharing his ideas and to establish contacts with carmakers and research labs. Over the years, he met with numerous experts, many of whom were sources of inspiration and information, and several of whom encouraged him to persevere. He very quickly understood the advantages of the variable compression ratio (VCR) and envisaged its multiple applications.

Vianney RABHI filed his first patent concerning the variable compression ratio engine in 1991. He met with different experts and soon realized that his idea had a certain number of crippling faults. He therefore established a list of the “indispensable” characteristics of a VCR engine and assessed “what must be done” and “what must not be done” in this field. He studied hundreds of VCR engine patents as well as literature dealing with these types of engines. He observed the recurring features in the design of VCR engines but none met his specifications. His first conclusion was that it seemed impossible to design a viable VCR engine, at least from a functional standpoint.

Six years later, in 1997, Vianney RABHI came up with the idea for the principle of MCE‑5 VCRi while looking at an elevator door. He remarked that the first half-door traveled at twice the speed of the second and that a gear and rack system allowed this motion. This inspired him to design a first rack connected to a piston, a gear wheel connected to a rod and an anchoring rack that he used to vary the compression ratio. A few months later, he filed the first patent that would later become the basis of MCE‑5 VCRi. The selected principle fit his functional criteria but was extremely daring in terms of technology. Indeed, a gear system would be inserted between the rod and the piston. This had never previously been done in engines. As an option for his engine, he planned a variable timing intake valve to implement the Atkinson cycle.

During that same year of 1997, he once again got in touch with his network of experts. No one believed in the gear system but there was a lot of interest in the Atkinson VCR strategy. Between 1997 and 2000, he filed several more improvement patents concerning his gear idea to make it more feasible. The gear became a truncated one with guiding rollers and a rod-crank system. Since his project ate up all of his savings and his debt capacity, he was obliged to find a “sponsor” to finance the study to design the gear and racks. It was this new design and a realistic pre-dimensioning that led a major carmaker to finally take interest in the VCR engine that Vianney RABHI had called “MCE‑5”. This resulted in a first collaboration with this carmaker in 2000 that ran until 2004.

After having founded the MCE‑5 DEVELOPMENT Company in 2000, Vianney RABHI is now its Head of Strategy and Development. He drives the main strategic and technical orientations for the MCE‑5 project.

« Over these last thirteen years, the MCE‑5 project had been an extremely rich technological and human adventure. The tests, the failures and the returns to the drawing board were all part of the adventure but the results now obtained from MCE‑5 VCRi are edifying from both the economic and energy standpoints. MCE‑5 VCRi is a technological leap forward enabling the control of the compression ratio without any compromises. This approach is important today for current identified and implemented strategies but it will be crucial for future strategies that we know will be extremely demanding. »