1) VVT explained:
https://www.youtube.com/watch?v=oHn9dnweSTE
2) Why your c-14 isn't a zx14
https://www.youtube.com/watch?v=TXAQQnbF7OM&t=71s
https://www.youtube.com/watch?v=oHn9dnweSTE
2) Why your c-14 isn't a zx14
https://www.youtube.com/watch?v=TXAQQnbF7OM&t=71s