Abstract
Improving fuel consumption without affecting the engine’s performances, reducing the exhaust emissions and achieving a good combustion process are the aims of this research. One of the found solutions is using gasoline – alcohol blends with an advanced airassisted direct injection (DI) system for a two-stroke- engine.
This DI system is manually regulated in order to obtain optimal parameters for maximum engine output and lower exhaust emissions. The engine type used in this experimental research is an Schnürle full loop two-stroke spark ignition (SI) engine, which operates at high engine speeds.
The results obtained with the conventional fuelling system -the carburetor-, are compared to the results obtained with air-assisted DI injection system. The combustion characteristics and the resulting emissions obtained during the tests were analyzed and evaluated.
Fuels that were used are super gasoline and different gasoline-alcohol blends. In order to analyze the influence of gasoline – alcohol blends in a 2-stroke SI engine, at different operating conditions;
By increasing of CR the engine efficiency increases. Especially by using fuel blends and pure alcohol the efficiency increases substantially so that a less fuel consumption is the result.
Working with alcohol blends requires the start of ignition (ignition point) to be delayed or set earlier in order to achieve the best combustion process behavior. The air – assisted direct injection system and gasoline – alcohol blends result in achieving a higher engine torque, a good combustion process and low exhaust emissions.
KEYWORDS: Gasoline, Alcohol Blends, Combustion, Emissions, Torque