The effect of imparting swirl motion to the fuel spray and combustion air streams on thermal flame characteristics is experimentally investigated using a horizontal water cooled combustor. A pressure swirl atomizer with a narrow nozzle of 0.4 mm diameter is used. To impart swirling motion to the fuel spray, the atomizer spin chamber is designed to have four tangent-perpendicular passages. Also, to possess swirling motion to the combustion air, the hub diameter ratio and the vanes angle of the combustion air swirler are changed leading to a change of the air swirl number. Both of the fuel and combustion air streams are co-swirled keeping the air-fuel ratio constant at 19 for the seventeen runs. Very stable flames are formed. Gas temperature distributions are measured along the combustor. Overall heat transfer rate to the combustor wall are determined. The highest heat flux value 67.7 kJ/m2.s is obtained by combining the best designed parameters of the spin chamber and combustion air swirler.