Wouldn't engineering encompass the communication and expectations? When you design a skyscraper, you need to know what sorts of loads is expected on each floor, any height restrictions in the area (are there airplanes around?), etc. When you design a literal engine, you need to know if you're optimizing for weight or power or raw RPMs.

Perhaps you're using the word "engineering" as a synonym of "implementation" (which could work); I'd have thought it was more "design" though (in a technical sense, though I'm sure it might cover some of the aesthetic sense too).