Textron Lycoming IO-540 Series Operator's Manual page 112

TEXTRON LYCOMING OPERATOR'S MANUAL
SECTION 7
0-540 & 10-540 SERIES
The corrosion preventive oil to be used in the foregoing procedure should
conform to specification MIL-L6529, Type 1 heated to 200°F./220°F.
(930C./1040C.) spray nozzle temperature.
NOTE
Oils of the type mentioned are to be used in Textron Lycoming aircraft engines
for corrosion prevention only, and not for lubrication. See the latest edition
of Textron Lycoming Service Instruction No. 1014 and Service Bulletin No.
318 for recommended lubricating oil.