{HEAD ~ The secondary lobes} cause {TAIL ~ an associated valve} to open slightly and close completely prior to the normally expected valve opening caused by the primary lobe 
cause
{ HEAD ~ The secondary lobes } cause { TAIL ~ an associated valve } to open slightly and close completely prior to the normally expected valve opening caused by the primary lobe
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH