I found that if I cranked up the mixture to maximum rich, which at that point gave me 14.5 GPH burn rate, that I could keep the rpm above 4000 rpm.  Naturally all that fuel going through the bad rotor was not producing any meaningful power and I might have been leaving a "afterburner" flame (don't know),but the engine rpm stayed around 4200-4400 rpm.  Besides, I was fully loaded with fuel, so did not mind get rid of some of that stuff prior to landing.