Baeta, J., Valle, R., Barros, J., Amorim, R. et al., "A New Concept of a Flex Multi-Fuel Engine," SAE Technical Paper 2004-01-3427, 2004, doi:10.4271/2004-01-3427.
The new trends of the automotive market require the application of new technologies to a concept of engines, which allows for the use of different types of fuel. The multi-fuel engines available in the market display only one compression ratio, therefore being subject to optimization, as to obtain maximum efficiency the engine must work with a variable compression ratio. Although technically possible, this procedure is not considered feasible for a low-cost product. This work proposes a system, which allows for each type of fuel to attain peak efficiency through a variance in the engine intake pressure and without changing its compression ratio, a feature that can be added to a low-cost product. The gains obtained with this project will be shown in each stage of the experiment and compared to those of the original configuration of the engine. The methodology to be used is the DOE - Design of Experiment. With this work we intend to create an alternative optimizing concept for the 1.3 8v FIRE FLEX MULTI-FUEL engine to allow it to attain peak efficiency when one of the following types of fuel is used: Gasoline E25, E94 ethyl hydrate, any level of mixed Gasoline E25 and Alcohol E94, and CNG.