Oil Cooling; Turbocharged Lycoming IO-540
Hey guys I would like to get your inputs and comments on an issue I am working on. It goes about powerplant cooling tests and more specifically about cooling of the oil in a turbocharged Lycoming IO-540 engine. Our project is to develop an STC whereby we add a turbocharger and new propeller to a Type Certified aircraft.
I’ve noticed from the Lycoming Engine Installation Manual that for the developmental cooling tests both temperatures of the oil into and out of the oil cooler should be measured. This makes sense to me as one could then use this information to establish the efficiency of the oil cooler and the oil cooler arrangement.
However our client is concerned about the possibility of higher oil temperatures elsewhere in the engine, which brings me to my question; is it possible to have localized peaking of the oil temperature elsewhere in the oil cycle, which might lead to thermal degradation of the oil? 
In my opinion, I believe that if we stick to the test requirements and limitations as specified by the OEM for the oil in, oil out all should be well, however, I would like to invite comments from anyone who has experience in this field.
Where do you anticipate the highest temperatures would be? Also, do you think it is possible to exceed of the safe temperature limitations for both SAE-J1966 (Mil-L-6082) and SAE-J1899 (MIL-L-22851) oil? Please keep in mind that the aircraft will be used for skydiving purposes and the abusive nature of such operations (i.e. High power settings for sustained periods, rapid descents and, most likely, improper rundown and shutdown of the turbocharger…
). From the data measured already on the aircraft, I know that the temperature of the oil coming out of the oil cooler during the critical climb test was approximately in the order of 81 degrees C. This is well below red line of 118 degrees. At this stage, I do not know the oil temperature going into the cooler but will measure it shortly.
Thanks,