At the end of last year I fitted an air/oil separator to the engine. This was an effort to address high oil consumption (1 quart every 3 hours). I was always finding a lot of oil on the lower cowling after longer flights, and also finding oil streaks on the prop. Those oil streaks were unburnt oil.
Until last weekend, when I flew to Santa Fe, Farmington, Aztec and Telluride, I had insufficient operational data to determine the impact on oil consumption from fitting the air/oil separator.
Preliminary data from the trip shows that oil consumption has improved, but not greatly. I am using 1 quart every 3.5 hours.
On Saturday I had John Hooker of J&S Aviation remove and inspect the lower plugs after I had flown up to Sherman running with the mixture full rich. None of the plugs showed any evidence of oil fouling; they looked perfectly normal.
I am coming around to the point of view that I have done all that I can to remedy the oil consumption issue, short of re-honing the cylinders and fitting new rings. I am not prepared to do that right now. The only issue with the current oil consumption level is that I cannot fly for more than 6-7 hours without installing a catch-tank...but since I never stay in the air that long, it is not a short-term issue.