The longitudinal axis of each engine cylinder intersects perpendicularly to {HEAD ~ the axis} of {TAIL ~ the engine power shaft} 
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The longitudinal axis of each engine cylinder intersects perpendicularly to { HEAD ~ the axis } of { TAIL ~ the engine power shaft }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL