I broke in the solid flat tappet in my car now with the inner springs out and that was in 2011 as its still going strong. In fact I have never wiped a cam lobe on any flat tappet cam. Dwayne Porter told me the biggest enemy to rollers is valve float as you dont want the roller lifters slapping the cam in valve float which can damage a roller so you want to run enough spring pressure so that if you race your car you wont go into valve float which can damage a roller needle bearing. Ron