What was found
(CAN) AFTER DEPARTURE DURING CLIMB-OUT, THE ENGINE BEGAN TO LOSE POWER. THE PILOT TURNED BACK TO THE POINT OF DEPARTURE, THE AIRCRAFT MADE A FORCED LANDING 38 MILES EAST OF THE BASE. THE AIRCRAFT WAS RECOVERED AND THE CAUSE OF THE POWER LOSS WAS DETERMINED TO BE THE FAILURE OF NR 4 CYLINDER HYDRAULIC LIFTER, WHICH PREVENTED THE EXHAUST VALVE FROM OPENING.