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