I have said this before but I will repeat it. If you really want to get a handle on what a set of cams is doing then spend some time and produce a set of lift versus engine rotation, every ten degrees of engine rotation which is every five degrees of cam rotation. Once this is plotted out the one can see what is happening. The four degree BTDC equal lift system might be OK for well known cams but if you are playing about with cams with unknown qualities then it will pay to do the job properly. If you can use a spread sheet then you can produce the graphs you need with very little effort and you can also use the same spread sheet to show the velocity and acceleration curves. If you cannot do that then if you send me a list of lift versus engine degrees then I will set up the whole spread sheet for you and, if it is of interest to others, put the results on here.