The crossword solution for the term 'eccentric piece' is CAM, which stands for camshaft. A camshaft is a cylindrical rod that is used in internal combustion engines to open and close valves. It is an essential component of the engine, as it helps to control the timing of the engine's intake and exhaust valves. Camshafts are typically made from steel or aluminum and are designed to be durable and reliable. They are often referred to as 'eccentric pieces' due to their unique shape and design.