Originally Posted by millemk

Great write up in Wikipedia. Now need to add more detail, maybe from the mechanical experts in our forum? Yes, the two chain system (separate chains driving each cylinder bank) was added to 2nd gen and in my opinion a key change as important as the dual port and direct injection. This two change system has been previously described in the forums, I believe in the www.f150ecoboost.net forum with very detailed information provided by RMB_Ryan who is a supporting member and avid engine builder. See https://www.f150ecoboost.net/forum/1...rformance.html