Abstract: A portable crop material dryer system for use with a flexible elongated bag in which harvested crop material is placed in situ. The dryer includes an internal combustion engine driving a blower for movement of air through the flexible container. The cooling system for the engine is connected to be in series flow relation to the air blower so as to heat the air and increase the drying capacity of the system. A burner may be connected to further increase the heating of the air and the power output of the engine may also be used to drive a generator for auxiliary purposes.