variavel0=<b>Felipe Soto Pau</b> - felipesp@sc.usp.br USP- Universidade São Paulo
<b>Antonio Moreira dos Santos</b> - asantos@sc.usp.br USP- Universidade de São Paulo
<b>José Antônio da Silva</b> - jant@funrei.br USP- Universidade de São Paulo
<b>Rodrigo Fernando Estella dos Santos</b> - santosrf@sc.usp.br USP- Universidade de São Paulo
<b>Abstract.</b> The emissions level of CO, CO2 and NOX was obtained for a engine with typical compression rate alcohol-fuelled engines  (11:1),  in  partial load  of 60%  and  2500  rpm,  using  alcohol-gasoline  blends  in different  proportions.  The  influence  of  the  percentage  index of alcohol mixed to the gasoline was evaluated with respect to the poluentes emission. For each test the ignition timing and air-fuel  ratio were varied for each blend aiming the best performance of the engine. From the pressure curve inside the combustion chamber a  detonation  index  was  obtained  to  verify  the  combustion  characteristics.  The  results  demonstrate  that  the  CO2  and  NOX  indexes  of  emission decrease with larger ethanol addition, while the CO results have shown more favorable operation whit leaner blends for the  same indexes of emissions.
<b>Keywords.</b> Internal Combustion Engines, Emissions, Blends Ethanol Gasoline.