An apparatus and method for trimming a contoured non-round workpiece includes a torch for flame treating or trimming the workpiece by impinging a flame on the workpiece, a holding member for supporting the workpiece, the holding member being rotatably mounted relative to the torch, and a control member for cooperating the holding member with the torch so that the torch follows the contour of the workpiece when the holding member is rotated relative to the torch. The control member generates an electronic image of the workpiece and guides the torch along the contour of the workpiece in accordance with the image.