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As to the detergency, the additives found in API oils will deposit on the valves
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API engine oils are designed to hold water in suspension so it can be evaporated by the heat of the adjacent combustion process, while special compressor oils drop the water out of suspension so that it collects at the bottom of the crankcase and doesn't circulate through the bearings.
My experiences match these. I had a couple of Ingersoll compressors, 20 hp each if memory serves (maybe bigger) with continual valve problems. Chevron recommended straight 40 wt. diesel engine oil, but I wasn't satisfied with the operation. I checked the original operating manual, considered the ambient temperatures as referenced in the manual, and switched to a iso 320 machine oil--like a 60 wt non-detergent turbine oil while we were in the Tropics. Great service. Back to 220 when out of the tropics. Different compressors (Hamworthy 450 psi for diesel start air), not such a warm location, iso68 (like a 20 wt) hydraulic/turbine oil was used. These made a lot of water--I think the water cooled intercoolers and aftercoolers might have been too cool. Draining daily was a must.
So--non-detergent is good. Match the viscosity to the temperature as indicated in the owner's manual.