Found it:

Quote:
All cams for S&S X-Wedge engines feature the S&S Easy Start automatic, mechanical
compression release. The ease of starting with the Easy Start cams, coupled with
the fact that compression ratio does not increase proportionally with displacement
in X-Wedge engines, allows cams to be used with a wide range of displacements.
Production cams for X-Wedge are designed to be “non-interference” cams. That
means that if the valve train were to stop for any reason, there is enough valve to
valve, and valve to piston clearance to avoid engine damage from valves contacting
each other, or the piston.


From this pdf:
http://www.sscycle.com/uploads/catalog/53/6%20Xwedge_WEB.pdf