our engines are different. we have duel cams. one is for the intake valves and the other is for the exhaust valves, not low and high rpm like the vtecslightly off topic but a rather silly idea crossed my mind-
as everyone knows our engines are twin cam. i assume one works during low rpm for fuel efficency and the other cam kicks in at higher rpm for better high rev power. suppose you swapped the cams out but used something relatively mild for the low rpm cam and a crazy ultra aggressive one for high rpm... would this turn the zetec into a vtec? if this is possible (which i doubt) would it need both, new camshafts and new gears?
now before everyone flames me for puting zetec and vtec in the same sentence i assure you this is purely out of interest.