mechanical vs mechanical related

dear sir
i have one question i hope you can plaease help me i am confused
about something
there are mechanical aspects of engines(pistons) and there are mechanical related aspects of engines these are electrical(engine bloc), chemical(fuel mixture)
can you say that not only electrical and chemical are mecahnical "related" aspects of engines but also mecahanical aspects are mecahical "related" aspects.

The electrical and chemical aspects are not mechanical.
Consider a spring in an engine. The metalurgical properties of
the spring could be considered a mechanical related aspect.