[Jay S]

I frequently run solid lifters on bigger HR cams. But I zero lash the solid lifters cold and let the hot expansion be the lash. There is light friction on the pushrods, i don’t use a feeler guage when I do it. The cam does not loose much duration doing it that way over HR lifters. Engine master did a test like that a few years ago and gained 8HP thru the entire power band over a side by side test with a HR lifters. I have ran lash, but it is easier to do and overall works best with no lash set cold. We use the same valve springs as the cam would with a HR lifter. I do add some extra seat pressure though depending on the set up. The engines I have done are 6500 to 7000 RPM street and strip engines and .640 ish lift 240 to 260 @.050”. There are not many mechanical roller profiles that I know of that can do the same thing without another 100 lbs of spring. Which is my reasoning when doing it.. When it needs SR springs I run a SR profile. I have never been back into reset the lash, they run pretty quite. Some are quite enough you can tell they have roller cams.

More lash equals less duration at the vale, same as any mechanical cam.