A process for cracking a heavy hydrocarbon feedstock containing non-volatile components and/or coke precursors, wherein a stripping agent is added to the feedstock to form an enhanced hydrocarbon blend which is thereafter separated into a vapor phase and a liquid phase by flashing in a flash/separation vessel, separating and cracking the vapor phase, and recovering cracked product. The stripping agent increases vaporization of the volatile fraction of the heavy hydrocarbon increasing the maximum feedrate capacity of the furnace.