Does the “Material Set” come with everything I need to build my engine?

The short answer is no. 

Generally you must come up with and use your own metal stock. 

Material Sets/Part Kits generally contain items that are usually hard to get or obtain for a reasonable price in a small quantity, i.e. bearings, Delrin (a form of plastic), graphite.  Each engine page describes EXACTLY what is included in the parts kit.