Understood. And thanks for that.3V Performance wrote: ↑Sun Oct 10, 2021 1:17 pm From my spintron experience ( we own 2 ) the problem is EVERYTHING affects everything in a dynamic state. Sim's can help with understanding but real world most always shows unwanted compliance or deflection that was never figured into a sim program. The results very AND are always changing with rpm. Intensity number can be misleading because of where it is on the lobe. We have moved it up and down 5-10* and kept the same amount and completely changed the valve motion and stability. Our facebook page 3V Performance has some cool 11,000+ rpm spintron videos for those who have not seen one run.
Now that said, is this to say that by presenting those two profiles in question, and not actually measuring them on a Spintron that it can't accurately be stated that one lobe will work with a given valvetrain and the other will not?
I can see how that would be the case.
My hope is that someone has that data.
If I refer to Lunati's catalog (or a special edition section of their catalog from several years ago) there are two listings for hydraulic rollers. One labelled as a their Pro-Power Endurance Grind and the other as the Super-Profile Hi-Po Street & Strip Grind.
Only seat to seat and .050" values are given along with the lobe lift.
As an example from the middle of the page:
Both are intended for use with a variety of rocker ratios.
Is this sort of description something that can be transferred to other brands such as those in the 1st post? Or are the descriptions just marketing hype?
I can say from experience that COMPs XE lobe was much quieter at 276/224 than their XFI lobe at 274/224. Not much of a spread but a noticeable difference. I'm not so sure I'd want to run that XFI lobe in an endurance environment. It was pretty slick on the street though and it liked the drag strip too.