20240622007219I

On 6/22/2024 at approximately 09:09, the aircraft was lead of a 3-ship to depart from rwy 17 at Colorado Air And Space Port (cfo). During power-up and taxi, the A&P certificated pilot noticed a bird flying at the end of the runway. The pilot kept the bird in sight during the takeoff roll, then saw the bird dive out of sight. At rotation speed, the pilot saw the bird come back into view and thought it might have struck the airplane through the propeller. Pilot did not immediaately notice any abnormal instrument indications. Shortly after rotation, he thought that the engine seemed not to be producing normal power and noticed engine oil temperature rising rapidly. The pilot decided to abort the flight and manuvered to land on rwy 26. At this time, the pilot noticed the engine oil temperature was above high temp red line. Pilot declared an emergency, landed on rwy 26, and taxied off the runway. During initial inspection, the pilot found no external damage and no vidence of bird remains on the propeller, cowlings, and engine. During subsequent inspection in the hangar, pilot tested compression in all cylinders which were within normal limits. When draining the engine oil, the pilot noticed it contained several metal flakes. Further inspection of the oil filter found many more metal particles and shards. The pilot/mechanic removed the engine and sent it to the shop for further analysis and/or repairs. Engine maintenance logbook shows engine ttso is at 1000 hrs. Manuafacturer’s tbo for the engine is 1300 hrs. Pilot stated that performance typically starts declining around 1000 hrs ttso. The pilot stated that airport officials found remains of two birds on or near the runway. This was confirmed by interview. And photos. The remains were shipped to the smithsonian institute for species analysis where it was determined that the condition of the remains were not consistent with a birdstrike. Lacking evidence, the NTSB ruled out birdstrike as a contributing factor.