AFTER APPROXIMATELY FORTY MINUTES INTO THE FLIGHT AND WHILE THE AIRCRAFT WAS 8,000 FEET ABOVE THE TERRAIN, THE ENGINE FAILED AFTER THE PILOT CHANGED THE FUEL SELECTOR FROM THE RIGHT FUEL TANK TO THE LEFT FUEL TANK. THE PILOT AND CFI PASSENGER FAILED TO USE THE EMERGENCY CHECKLIST AND WERE UNABLE TO RESTART THE ENGINE. THE AIRCRAFT LANDED IN AN APPLE ORCHARD. THE WRECKAGE EXAMINATION DISCLOSED NO EVIDENCE OF ANY FUEL IN THE LEFT FUEL TANK. THE ENGINE OPERATED NORMALLY DURING THE WRECKAGE EXAMINATION.