Ok let's try one more time. My theory on this is>>>>>>>>>>>>>>>>>>>>
Agressive leaning does not equate to LOP
The purpose of LOP is not solely to increase MPG although that is a nice result.
If you look at the earlier graph you will see that there is a point on the lean side where BSFC peaks. At that same point the down slope of the CHT and the Down slope of the ICP is significantly steeper than the down slope of horsepower.
No body is claiming magical numbers that equate to a free lunch. What we are suggesting, based on proven fact is that there is a confluence of the performance curves on the lean side of peak that:
#1 decreases Intra cylinder pressures in greater than linear proportion than it decreases available horsepower thus suggesting prolonged engine life.
#2 decreases CHTs and EGTs in greater than linear proportion than it decreases available horsepower thus suggesting prolonged engine life.
#3 decreases fuel consumption per horsepower produced in greater than linear proportion to a decrease in available horsepower thus decreasing fuel consumption or increasing MPG.
At this same horsepower setting on the ROP side the CHTs ICPs EGTs are all significantly greater as is fuel flow.
No one is suggesting that you lean so aggressively that the engine is on the verge of stopping., or that you have decreased horsepower to the point that a fart in the cockpit stuns your fixed pitch prop into silence.
LOP operation is a process of fine tuning your engine so that all cylinders are operating on nearly the same curves for CHT EGT ICP and then finding a spot on that curve that decreases the stresses inherent in internal combustion engines, while providing acceptable power to perform the task at hand.
If you are leaning a fixed pitch prop to the point that the plane destabilizes in minor air currents you are not running LOP you are leaning too aggressively.
No one who investigates the subject is saying Lyc or Cont are stupid. Both organizations have recognized that their engines run just fine on the lean side.
Lyc and Cont rec ROP because they realize that most pilots will not properly tune their engines nor instrument them to find the proper point on the lean side of peak safely.
As far as being a Deakin fan I admit I am unabashadly a big time Deakin fan, primarily because he is usually right and backs up his conjecture with documented fact or experimental data which is more than can be said for the Aussie investigatory board who present no solid evidence to support their conclusions. Yet many blindly accept their finding as fact. I would not accept outrageous theories even from Deakin if they were just speculation, innuendo, or a continued propagation of OWTs.
The following is a quote from Bob Nuckolls that I find particularly suitable to the discussion of LOP. The words in red are mine.
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists;nor does it reside in some fraternity of the uninformed purveyors of old wives tales, nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >