do you have any details of what ignition mapping your using? I am looking for what particular advance you are running at full load and max revs

It is currently running 38 BTDC at 7,200 and full throttle, which I believe is too much. someone at work who used to build race engines reckons on 28 to 30 for a 16 valver with a decent shape combustion chamber, but then again Zetecs might have a requirement for more advance.

Details are Megajolt ignition for a Zetec Silver-top on twin 45s, Kent uprated cams (not sure which) and standard compression ratio.

Ed

Most engines get to max advance at 3600 to 3800rpm then flat line letting vac adjust for part load
You can mirror the standard advance as stated in a Haynes manual and advance until it pinks then retard a couple of degrees
Higher lift cams with standard compression increases burn time so you may need less advance than standard
There are plenty of Zetec Megajolt maps on the web and Autosportslabs has a small library

ISTR the K16 which has a similar combustion chamber maxes out a 29 BTDC
A wilder cam demands a little more advance than standard cam and a larger bore also has a simliar effect so I would say 30 to 32 BTDC.