In this archive demo video from Morris Motors and presented here by the fine folks of British Pathé, we see the process of constructing an engine for a car in the 1930s and the different forms of power that allow it to happen. Much different than the micrometer robotic technology used today. By the way, if you have never toured an automotive manufacturing plant, you really should. It is amazing.
It is extremely cool to see how engines were built in a completely analog manner and about five decades before computers were a normal thing. It is also interesting to hear terms explained such as forging, casting, broaching, lapping, hogging… many of which are becoming lost arts.