What was found
FUMES IN COCKPIT ON TAKEOFF ROLL TILL ABOUT 5K FT. REQUIRED CREW TO DON O2 MASK IMMEDIATELY AFTER TAKEOFF. ODOR OF BURNT RUBBER/ENG SMELL MAINLY ON CAPTAINS SIDE. FO DID NOT DETECT ODOR. ODOR CLEARED BEFORE CREW COULD SECURE ANY EQUIPMENT. NO FURTHER OCCURRANCE REST OF FLIGHT. REF B757MM 21-00-01-3 AND JRH,RAN APU, TESTED /RAN ENGINES AT MAX STATIC EPR.COULD NOT DUPLICATE ANY BAD OR SUSPECT ODOR.RAN PACKS NUMEROUS TIMES FROM HOT TO COLD, NO ISSUES.NO FINGINGS IN ALL OTHER INSPECTIONS. A/C GOOD FOR SERVICE.