Rolling tool for forming a valve seat retainer

摘要

A valve seat retainer is formed having a flange that extends over the valve seat and that applies both a radial and a longitudinal force to the valve seat. The flange extends an order of magnitude further than typical prior art valve seat retaining flanges. The flange is created by a rolling method with a roller having a unique surface profile. The roller surface has a pair of spaced ridges with a groove in between, and a curved convex surface adjacent to one of the ridges. When a downward force is applied to the roller, the curved surface on the roller causes the roller to move radially inward while at the same time material from the upper surface of the engine block is disposed in the groove and is moved to create the flange.