What was found
LOWER ENGINE COOLANT HOSE AND EXHAUST SCAT HOSE ARE IN CONSTANT CONTACT DUE TO INSTALLATION DESIGN. CHAFING CAUSED WIRE FROM SCAT HOSE TO PUNCTURE LOWER COOLANT HOSE. SUBSEQUENT LOSS OF ALL COOLANT CAUSED ENGINE OVERHEATING. WHILE PILOT WAS DETERMINING CAUSE OF HIGH CHT INDICATION, CHT GAUGE WENT TO ZERO. ENGINE WAS MAKING NORMAL POWER AND ALL OTHER INDICATORS WERE NORMAL LEAVING PILOT UNSURE OF PROBLEM (FAULTY GAUGE OR ENGINE OVERHEATING). UPON RETURN TO AIRPORT AND INSPECTION OF ENGINE IT WAS DETERMINED ENGINE BECAME HOT ENOUGH TO DESTROY CHT INDICATOR IN CYLINDER HEAD. THE VISUAL ACCESS TO THE HOSES IS VERY LIMITED, THE ONLY WAY TO INSPECT WILL BE TO REMOVE THE SCAT HOSE. HOSES ARE IN CONSTANT CONTACT AND NEED TO BE REROUTED OR REDESIGNED. THIS OCCURRED ON THE RT ENGINE. THE LT ENGINE IS ROUTED DIFFERENTLY BUT THE HOSES ARE ALSO IN CONSTANT CONTACT.