The determination of IC engine inlet port geometries by reverse engineering

Reverse Engineering is used to determine the inlet port geometry of a diesel engine. The case described illustrates a general problem where the precise nature of manufactured components relies heavily on the skills of pattern makers and foundrymen. Two methods are used, one in which the geometry is determined by used or silicon rubber moulding and one by machining planes off a cylinder head. In the latter case the geometry was measured by a contact probe on a CMM, generated in the CMM software files and transferred to Pro/ENGINEER® data files. The procedure, and the difficulties experienced with applying surface modelling to the generated data are described. General conclusions are drawn on the present state of reverse engineering as a means of adjusting CAD data to ensure conformance to specification.