The article presents the application of modern metrological measurement methods to reproduce the geometry of complex components of marine self-ignition engines. Geometric dimensions and shapes were obtained in tests of new and operated marine self-ignition engine components. Cognitive aspects of two- and three-dimensional images were used to obtain data for modeling in design and technology development, diagnostics, and tribology. The scientific objective is to determine the geometry of the main components of the fuel injection subsystem after manufacture and operation for quality control and condition monitoring. Geometry tests were performed using a volumetric scanner, a laser scanner, an optical measuring machine, a high-precision coordinate measuring machine, digital microscopes with a resolution 0.000 01 mm, and measurements of friction forces and the mass flow of oil and air on the constructed innovative test benches. The relative uncertainty of the fuel mass stream rate does not exceed ± 0.5%. Measurements were taken of surface micrometer readings, external and internal component dimensions, silicone castings, shape and position errors, and profile shapes that affect fuel injection. The geometric measurements of a set of points were obtained to elaborate digital images of structures for design modeling and noninvasive diagnostics. The author’s scientific contribution is the evaluation of the geometry of small internal spaces of the fuel injection equipment using X-ray tomography, measurement of friction in precision pairs, and a method for estimating limit values. Multiple regression was used to select the optimal global state feature of the technical condition for quality control, with a coefficient of determination of 0.880.