A cam plate is disposed in {HEAD ~ the engine housing} and supported for rotation about {TAIL ~ the longitudinal axis} 
A cam plate is disposed in { HEAD ~ the engine housing } and supported for rotation about { TAIL ~ the longitudinal axis }
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL