Jim,

 

With all due respect, did you mean to say that you ‘now only run ROP because of too high EGT's when LOP’?  I’m neither an engine expert nor a sleeper at Holiday inn, but EGTs are indicators of nothing, other than as the mixture is leaned out, the EGT will continue to rise until you go lean of peak, at which point, it starts descending on the other side of the mixture curve.  Perhaps it’s a play on words or imprecise use of words, but you will have the same EGTs on both sides of the mixture curve.  By definition, if fuel injectors for your cylinders are properly balanced, you can not have high EGTs LOP.  LOP ops indicate that you have gone past the peak EGTs. The same as your speed well be 50 mph twice when making a trip at 70 mph (the peak speed)…once as you speed up to 70 (peak EGT) and once on the way down (LOP).

 

ROP operations, at least for Lycomings, will result in higher fuel consumption, higher peak cylinder pressures, higher CHT and potentially accelerated valve degradation.  Of course, LOP operations assumes 1) use of injectors, 2) the injectors have been properly balanced, 3) that you have EIS information that allows you to track each cylinder. 

 

You may wish to research the GAMI website, Air Performance website and other sources regarding the relatively merits of ROP and LOP operations.  Then again, perhaps our specific engine is different, in which case, forget everything I just wrote.