Looking at the rocker arm configuration on the angle valve engines, I am trying to figure out how gravity doesn't allow the rocker shaft to work it's way out, and fall towards the center of the Cylinder. There is no hardware in the parts manual that holds these in place, just the "access" hole on the top of the cylinder to allow for the removal. Here is a picture of what I am asking.

cylinder4.jpg



Any ideas or knowledge?

Thanks!