I figured that variable duration didn’t last long. Seems like there were a lot of failures involving hammering the valve train when set loose and wiping lifters out when set tight. IIRC, solid don’t work too well when they run completely out of lash. Don’t contend too well holding back combustion pressure at TDC. I’ve seen detonation go to pre ignition and wipe out a hydraulic in stout build before.
