The engine line at the Maxwell (1904 to ’25) factory located in Detroit, MI. on Oakland Ave. It appears that just before this spot on the assembly line, the cylinder heads were installed and the bolts hand tightened. If you follow the light-colored tracks on the floor left behind by the engine dolly wheels, the motors take a 180-degree turn here and begin down the next row where a worker is using an impact wrench to tighten the head bolts. Courtesy of The Old Motor