Oil pressure fluctuations
I have a Titan IO370 with 230 hours on it. Due to high oil usage, 5 hours per quart that never changed from day one, I had the engine cylinders honed and re-ringed, 2 cylinders were glazed. New break in was going well, temps down but high oil usage, 1 quart per 2 hours, hopefully that will improve. When I had about 10 hours on the "new" engine, I started getting oil pressure fluctuations.
I was steady at 78 psi for most of the life of the engine, it's high do to an inverted system, then after about 10 hours, it went slowly down to 68 or so, 49 at idle for landing. I was trying to fly with a lower oil quantity, 5 quarts, to see if I would stop using so much oil, a friend with the same engine and inverted system says 5 quarts is his engine's happy place. I put two quarts of oil in thinking it might be a quantity issue, it helped initially but now changes between 70 and 77 psi. I changed the oil pressure sensor, Garmin system, and cleaned the oil pressure regulator, had no positive outcome.
I guess I'd like to know if it's safe to fly this way, why the sudden change after 230 hours and ultimately the cause. Lots of experience here, please help. Thanks