Actually raising the fuel temperature to the vapourization point is what it sounds like they accomplished. The carburator to deal with this may have been quite complex. It may not have even been one as we remember them. The project If nothing else seems to indicate too much energy potential is lost when injecting small droplets over pure vapour into an engine.
Maybe there is yet some hope for the gas engine. I wonder how much energy was used to boil the gas off? Would not take much. Funny I do not remember reading about this back then or since.
Yet our fuel was so cheap by comparison to today it would have not made particularily large waves then. Some of this technology might get a curent new design car to a hundred miles per gallon one would think. The downside is it might have been discounted for mainstream applications because the process was hard to regulate or destroyed engines.
Who knows if we may hear of it again?