3. Constructive solutions

While the appeal of variable compression is easy to understand and accept, its practical realization is above all a technological challenge. There are many mechanical solutions for automatically and continuously varying the volumetric compression ratio, all of which have their advantages and disadvantages. However, in the context of a rapid market launch for variable compression ratio technology, certain design parameters must be respected:

• conventional parts (maintaining knowledge of manufacturing techniques, mechanical dimensions, material characteristics, reliability, etc.);

• combustion chamber, kinematics of the engine mechanism which have been the subject of a century of development;

• dynamic engine response (excessively slow control systems are not acceptable, especially...