Abstract: An insitu wet combustion process for the recovery of heavy oils from subterranean oil formations, such as tar sands, in which non-oxygen containing fluid, such as water, is introduced along with air cyclically to produce periodic high volume rates of injected fluid, great enough to increase the total sensible heat carrying capacities of the air and the vaporized fluid, such as steam, entering the flame zone substantially above the sensible heat capacity of the rock formation entering the flame zone, to substantially increase the temperatures of a downstream hot zone downstream of the flame front, without quenching the combustion.