Abstract: A rotatable engine supporting apparatus including a pair of spaced truncated bases, an engine supporting frame disposed between the spaced base on rotatable shafts extending through pairs of bearing assemblies mounted on the upper surface of each of the bases, one of the shafts being driven by a gear reduction motor located in one of the bases through a chain and sprocket arrangement; the engine supporting frame being of a generally rectangular configuration with shorter end members affixed to the shafts and longer side members extending between the end members, the side and end members being edge-reinforced I beams welded together at the corners with overlay corner plate reinforcements, the frame having removable engine mounting brackets extending inwardly from each of the side members, each of the mounting brackets having an angle section with two faces engageable with the side member, a plurality of spaced connecting sections extending transversely from the angle section to an engine engaging section, the