INFLT ENG SHUTDOWN. DIVERSION TO ALTERNATE.

Narrative

I TOOK OFF FROM TEB ON TRIP TO EAST HAMPTON; NY. APPROX 15 MINS AFTER TKOF WHILE I WAS CRUISING AT 2500 FT FRONT ENG (CESSNA 337) STARTED TO SHOW SIGNS OF OVERHEATING (CYLINDER HEAD AND OIL TEMP GAUGES). FRONT ENG COWL/FLAPS MALFUNCTIONED AND WOULD NOT OPEN. CYLINDER HEAD TEMP STARTED APCHING RED LINE AND I SHUT DOWN FRONT ENG TO PREVENT SEIZING UP AND POSSIBLE FIRE. I CONTACTED NEW YORK APCH AND ADVISED I WOULD BE LNDG AT FRG. I ALSO CLRLY ADVISED THAT THIS WAS NOT AN EMER. I WAS CLRED DIRECT TO FRG AND LANDED WITHOUT INCIDENT. FIRE TRUCK FOLLOWED MY ACFT AFTER LNDG AND WHEN I STOPPED AT RAMP; THE DRIVER OF FIRE TRUCK ASKED FOR CERTAIN INFO WHICH I GAVE HIM. HE ASKED FOR LICENSE AND MEDICAL CERTIFICATE. I CHKED MY POCKET AND NOT FINDING IT I ADVISED HIM I DID NOT HAVE IT. A SHORT TIME LATER; AFTER HE DROVE AWAY I DISCOVERED MY LICENSE AND MEDICAL CERTIFICATE WAS IN MY FLT BAG IN THE ACFT. I TOOK OFF COWLING OF ACFT AND AFTER SOME TIME THE FRONT COWL/FLAPS OPERATED NORMALLY. I CHKED WITH MY MECH WHO IS VERY FAMILIAR WITH ACFT AND HE ADVISED ME OK TO FLY ACFT PROVIDED ON EXTENDED RUNUP THAT ALL INST GAUGES OPERATED PROPERLY. AFTER EXTENDED RUNUPS AND HIGH SPD TAXI; I FLEW ACFT BACK TO TEB WHERE I HAD MECH CHK ACFT.