What was found
AFTER TOTAL ENGINE FAILURE WITH NO WARNING, ROTARY VALVE SHAFT WAS FOUND DEFECTIVE. ROTARY VALVE SPLINES WERE FOUND MELTED OFF. FAILURE WAS FOUND TO BE DUE TO ROTARY VALVE OIL BEING DILUTED BY WATER. WATER WAS FOUND IN ROTARY VALVE OIL TANK. SEAL HAD FAILED. INSPECTED THREE OTHER AIRCRAFT AND FOUND SAME PROBLEM. SUBMITTER STATED THIS IS AN EXPERIMENTAL AIRCRAFT, BUT A PROBLEM NEEDS TO BE ADDRESSED.