Alternatively bas circle can be measured if you have access to a DTI, surface table & some parallel bars etc - heck even a good lather could do it semi accurately. You can measure the bearing journal size & confirm its dimensions then use the dti to compare the base circle to the bearing journal. Similar approach on the lathe (lathe static obviously) run the slide in till tool just touches the bearing journal & take note of measurement, then do the same for the base circle. It wont be extremely accurate but it will give you an indication of how much has been machined from the base circle (I'm picking a fair bit 1 - 1.5mm). What I suspect is the cams have been ground to a profile that works well in other applications (IE: another type of engine) the guys have then figured "this works well in that motor, lets use it for VG30DEs as well) result not so good Have they sold plenty of these grinds in the past? I will see if my customer is a member here & point out this thread, he did a fair bit of research into all this when his was playing up, he may have some info that is useful. Also if you like ring Franklin Cam services (NZ), the guys are really helpful & have a lot of experience with grinding cams for these engines. Once I have finished tinkering with my eng the last thing on the list is to get some custom cams designed specifically for what I need. (still changing things & power is shifting about all the time) Link: http://www.camshafts.co.nz/Default.aspx For the short term we actually used a slightly dodgey technique & ran double shims under the valve springs, not sure I would do this for a customers eng though :rofl:
