Mini Fuel Rail - An Option for Cold Start System

The physical properties of ethanol make difficult the cold start of engines using only this fuel. The solution most adopted consists in the utilization of an auxiliary gasoline reservoir and the injection of this fuel when it is necessary. In this work, it is presented a new concept for the cold start system using gasoline injection that consisted in the use of a mini fuel rail, so called because of its compact layout that through the use of calibrated orifices allows the fuel injection as jets directly in the admission valves. It presents the CFD simulations, conducted to improve the system performance and the bench laboratory tests performed to evaluate the fuel distribution and to analyze the fuel jets.