OT: timing belts

Belts are used in production cars for a number of reasons: gears are noisy; using helical cuts etc to lower noise puts thrust onto camshafts causing other problems. Most gear drives are extremely noisy, usually the loudest thing under the hood. Camshaft thrust forces cause "walk" which is generally bad. Rubber belts are quiet, and reliable "enough". Our 96 Honda requires a new one every 60K? miles or so. The rambler, like most american, pre-1980, rear-drive cast-iron engines, has a steel belt, no recommended replacement interval. Mine's 17 yrs old. No reason to even check it for wear. I run synth oil, and LP doesn't cause combustion crud in the oil and lasts 15K+ miles per change, but I change every 8K or so. Nylon gears (for belts) lower noise even more, at slightly reduced life. Good oil change intervals eliminate most problems, eg. maintenance.