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Although the advantages of optical techniques for surface assessment have long been appreciated, the inherent limitations of such methods have meant that stylus techniques remain the accepted "standard" for surface assessment. The study of many engineering processes, such as those used for engine bore preparation techniques, have been based on stylus methods, although optical analysis may prove advantageous due to the face that 3D assessment may be achieved much faster. Optical techniques may become more feasible if a detailed comparison of results obtained from the two techniques is carried out, and shows the two methods are comparable. A study of this kind will help to develop optical assessment techniques which, although may initially be limited to specific processes, may prove useful in many production environments. This paper presents a study of established two dimensional models which have been applied to the characterization of the preparation of engine cylinder liners and bores. These models are extended to three dimensions and quantified using a three dimensional stylus measuring system consisting of a computer controlled Talysurf 5. Relocation techniques are then employed on the surfaces used for assessment and the finish is re-assessed using a computer controlled laser measuring system. It is shown that engine preparation techniques may be monitored using optical assessment. Thus, an alternative method of assessing engine preparation is proposed for optically based instruments.
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