Lycoming Service Instruction Data
I agree with Mel Asberry on his numbers. The following is copied from Lycoming SI 1094D item 9.
9. For maximum service life, maintain the following recommended limits for continuous operation:
(a) Engine power setting - 65% of rated or less.
(b) Cylinder head temperature - 400°F. or below.
(c) Oil temperature - 165°F. - 220°F.
(d) Turbine inlet temperature - maintain 100°F. on rich side of maximum allowable.
While it mentions TIT, this bulletin is applicable to all Lycoming horizontally opposed engines. This following is my opinion, but once again I agree with Mel; The minimum oil temp is indeed 165F, but you need to be at 180F+ to assure alleviation of condensation. Once again..my opinion only
Good Luck!