yes i know they arnt ecotec castings LOL just depends what version heads they are if they are early ZZP leftovers ide bin them LOL took them so many goes to get them anywhere near good wrong cooling passages too big and too small passages one casting didnt even have them at all LOL even mace wont post flow figures for them costs #### all to get a head flow tested why is there no figures??i wouldnt even look at them untill i had seen some sort of results/tests etc.set of hand ported cast iron heads will outflow these alloys as they come out the box
DW,
Have you seen the heads in person to make an accurate judgment? In regards to flow benchs, they vary worse then dyno's, so posting up flow bench figures using a state of the art SuperFlow bench, is definately going to different figures then ol mate running seven domestic vacuum clears, with just a manometer and everything else in between. Comparative testing on the SAME flow bench (or reputable ones), with accurate temperature/weather compensation etc is the only way to get meaningful results.
From feedback we've received from customers, with actual product experience and in the hands of professional head porters, these alloy heads flow about as well as a set of good factory ported heads out of the box. Where they really shine though is when they're ported, reaching flow far greater then the "best" factory ported head, with the simple fact that they have much more meat to play with, coupled with revised chamber and runner geometry off the bat