1970's Europe vote - file of UK

The video tutorial provides an overview of engine mechanics, focusing on the concept of building up blood flow within the system. It introduces the basic principles and processes involved in engine operation and how these relate to the movement and management of fluids, such as blood, within the system.

How might the phrase 'building up blood' relate to the functioning of engines?

Can you think of any other metaphors that use engines in a similar way? Please explain.