Originally Posted by kend
Thanks guys but what I'm looking for is.... why would you use a solid instead of a hydraulic? What does a solid do that you can't do with a hydraulic? Why are the factories now using hydraulic rollers, just for the decreased friction? I know the difference in construction and what a roller lifter can do as compared to a flat lifter, just looking for some "why" answers. Thanks
Most of the time to keep increasing hp with the same cubic inch you have to turn more rpm. You will hit a point that the spring will not keep the lifter in contact with the cam, so you have to increase spring pressure. You will then hit a point that the hydraulic lifter can not keep oil in it because of the spring pressure, it will beat itself or other valve train parts to death. The next step in the evolution was to go to a solid lifter at that point. Hope that answers your question.
Curtis