{HEAD ~ Certain portions} of {TAIL ~ the engine}, such as the flywheel, are left out of FIGS 4 6 to simplify the drawing 
of
{ HEAD ~ Certain portions } of { TAIL ~ the engine } , such as the flywheel , are left out of FIGS 4 6 to simplify the drawing
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH