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C85 High Oil Pressure

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GabeN

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Location
Anchorage, Alaska
I've done quite a bit of reading here but just want to have others check my thoughts and make sure I'm on the right track. Here's the details of how my engine is running:

C85-12
Phillips 20W50 oil
Oil temp 100-160*F
RPM 2250 Static, 2300 55mph climb, 2450 WOT level cruise
Oil consumption 1qt/7-10hrs
Compressions 74/80 lowest, 78/80 highest
Oil pressure: 45psi idle/cruise 50psi WOT climb

The oil pressure seems high compared to specs I'm finding. I checked the oil pressure relief valve and there are no washers and everything is clean inside. Pressure is the same after checking the valve. This engine has always made 45psi religiously and up to 50psi at WOT. I know the oil pressure gauge can be off but this seems like a very consistent measurement. Is this too high of an oil pressure or is my engine just very tight? This engine has also always had issues with blowing a lot of oil out of the breather (which I just re-routed and that helps); could that be a part of the high oil pressure?

Another thing that I've been wondering is about oil. Not to turn this into another oil thread but is 20W50 a good year-round oil? This plane gets flown in the winter on skis too so multi-grade seems like a good idea. A lot of people used to run Aeroshell 65 in the winter but it is no longer available as ashless dispersant. Can you just run regular mineral 65 all the time and would it help the oil pressure?
 

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