What was found
RETURNED, ACFT WAS GNDED. RT AFTER ROTATION, THE CREW NOTED A STRONG SMELL OF BURNING OIL & HAD SMOKE IN THE COCKPIT. THE CREW OXYGEN MASKS WERE USED IN THE COCKPIT ONLY SINCE THERE WAS NO SMOKE & ONLY AN ODOR IN THE CABIN. DECLARED AN EMER & THE ACT RETURNED WHERE IT LANDED SAFELY WITH NO FURTHER INCIDENTS. PERFORMED CABIN AIR QUALITY TROUBLESHOOTING IAW JC 43L00021001 & NR 1 ENG DETERMINED TO BE THE SOURCE OF ODOR. ENG WATER WASH PREVIOUSLY ACCOMPLISHED PRIOR TO FLIGHT & PERFORMED AMS SYS DRY OUT IAW EMM 72-00-00-100-801. NO FURTHER SMELLS NOTED, OK FOR SERVICE.