Hot Surface Ignition of Gasoline on Engine Materials

For vehicle fire investigations, the issue of gasoline hot surface ignition [HSI] on an engine component will arise. To address the concern usually two facts are required; the fluid's lowest hot surface ignition temperature for the vehicle conditions and the temperature of the component surface at the time of the fire origin. Three typical engine compartment surfaces were used to determine the HSI of gasoline; a nodular iron exhaust manifold, a stainless steel exhaust manifold, and a stainless steel heat shield. These components were used to conduct the bench tests for the typical regular and premium, summer and winter gasoline blends. Video tapes were used to acquire accurate autoignition temperature [AIT] data with thermocoupled parts. The investigation determined that the gasoline's HSI minimum values were dependent upon the materials used for the ignition surfaces rather than the grades of gasoline.