Quote Originally Posted by agjohn02 View Post
have you never seen a roller cam lobe next to a flat tappet lobe? they are very different. the goal is to open and close the valve as quickly as possible with the type of lifter you are using. flem's drawing is exactly what the comparison is like between a roller and flat tappet camshaft.
no flems drawings are not like a any lobe you will ever see. ive seen plenty of huge (.700+ valve lift) roller cams none had concave lobes. i have seen almost square lobes but no concave ones.