Assembly systems for the production integrated pre-assembly of engine parts are medium-sized assembly lines with up to 5 stations. They are used for intermediate installations embedded between cutting and subsequent cleaning steps. Typical project volumes range between 1.0 and 1.5 million euros. Cycle times of 30 - 180 seconds are common. The assembly systems have a high degree of automation. In most cases, a fully automatic assembly is set up using articulated arm or gantry robots as a linkage system. For small quantities, a semi-automatic system concept can be sufficient. Typical joining processes are screwing and press-fitting, often with subcooling in a nitrogen bath or oiling. Other integrated processes can be joining by heating, application of sealants and leak testing. Needle marking and laser marking are common for labeling. User industry is the automotive industry. Increasingly, also automotive suppliers can be found among plant operators. Typical workpieces are cylinder heads, crankcases and connecting rods. Pre-assembly steps include the press-fitting of valve seat rings and valve guides on cylinder heads, the mounting of bearing caps on cylinder heads, crankcases and connecting rods, the joining of closure elements such as balls and screws as well as the joining of cylinder liners in crankcases. In-line pre-assembly machines are integrated into the material flow of machining lines of cylinder heads, crankcases and other parts of automotive combustion engines. The assembly machine is virtually in line between the machine tools of the parts production. Not meant here are pre-assembly systems in engine assembly. Characteristic is the necessity of subsequent machining steps after the respective pre-assembly - or vice versa: the need for a pre-assembly before the machining can be continued. In case of the crankcase, for example, the crankshaft bearing covers must be mounted before the fine machining of the crankshaft bearings. Typical is also the sealingsm of corner-drilled channels for cooling water and oil by joining balls, bolts, screws or expanders as closure elements with a subsequent leak test.