Interesting, but apple sauce
RV7ator, John Siebold wrote: The guy who trashed his engine in the EAA link was running 100LL. Poor devil; it killed his engine. He was following Lyc recommendations about which there is a substantial body of evidence against/challenging/refuting many Lyc recommendations. For starters, search around AVweb for articles/columns by Jim Deakin about where to run your engine. Similar, but far less researched and referenced, are occasional fluff pieces in AOPA and other slicks.
I have read his articles. He he got a free set of injectors and wrote an article. I am sure they are great for large Continental. Most LOP operations that work are on 6 cylinder engines. Small Lycomings are going to get less advantage from LOP operations. INJECTORS: You know an injector is, a very simple piece of brass with a hole in it, that squirts fuel into the intake port near the valve. There are no secrets. Squirt Squirt. It is like the TV info-commercial and the "Fuel Tornado 2000" or "Fuel Magic-Magnets" you put on your car or truck's fuel system to improve HP and fuel economy. Once you pay all that money you have to prove it works to justify it (I never bought one BTW). You drive your car with more care to show it works.
FI systems for the Lycoming, like Airflow performance, come with well tuned injectors out the box. They will custom tune/ flight test your injectors on your plane for $300. There is more to it than just the injector. You not only have to match your injectors, but your whole engine. If your exhaust is imbalanced, have a weak jug or two, injectors are not going to do it all. You can always try for LOP operations, but your mileage may vary (pun intended). 4 bangers, FI or not, are not as good as 6-cyl in LOP operations.
Lyc has a lawyer problem. It's why ECI and Superior are encroaching on them, technically for lack of Lyc innovation, and financially because Lyc has a burdensome overhead buying their peace from clueless juries. You can be sure Lyc will never come out with some manner of operation different then they've always prescribed, lest some shark sue them for being wrong in the first place and that's why Uncle Willy CFIT'd.
I don't have any Textron Lycoming stocks, but I believe them more than I believe AvWeb who is writing about how great a product is. The company the invented the modern horizontal piston aircraft engines, making them for +60 years and has ten's of thousands of hours of test stand and flight test hours can't be too dumb. Law, Lawyers and legal issues a side, LOP is not a given, slam dunk, sure thing, works for all engines, installations and method of fuel metering (Carb, FI). Engines have been run well lean of peak for almost 70 years. They (engineers) know all about it. NACA (now NASA) did research in the 1940's on LOP operations with all kind of engines. Lycoming has done the same studies, this is old news. Lycoming does not say it can't be done, just it is not practical for small carbureted engines. You are not correct saying Lycoming will never change procedures. Lycoming calls for LOP operations on the Piper Malibu, with a large 350HP FI and turbo engine:
http://www.avweb.com/news/usedacft/182792-1.html , Why? It is worth it. What fuel savings do you think you are getting, really, on a MPG basis with a little 160-180 hp engine. I never read how much fuel LOP is saving over ROP and what the TAS is. I personally doubt you can get worth while LOP ops with a Carb, but I am ready to be amazed. I have heard of moving the butter-fly (slightly) to get better fuel distribution bias (front to back), but never tried it. Still it is apple sauce.
Where you and I diverge mainly is ROP. +75 or so is the WORST place to be, so I read often outside of Lyc, and completely contrary to your assertion. You can't hurt an engine LOP, but you can ROP. When my #2 and 3 are LOP, the others are near peak. CHTs are wonderful, which speaks more to proper air cooling than whether the EGTs are 25 or 50 degrees one way or the other.
Again LOP, if you can achieve smooth operations, than go for it. However most find it is not practical. As far as running on the ROP side and damage, that is not true. As long as you are below 75% power and the CHT and Oil Temp are acceptable you are safe. Lycoming recommends ROP and smooth operations for ECON. They don't specify an exact EGT but it is around 50F to 75F ROP. They recommend 100F-150F for best power. This is cool with Lycoming. No one is saying run at peak EGT. I understand how LOP works and why it should not damage your engine, you are making less power and therefore making less heat. No extra fuel is available to cool the engine, but it is not needed. All this LOP stuff is good if you can get smooth operations, and all cylinders are LOP by 40F-50F. Even than, fuel saving on a small 4-cyl Lycoming is smaller than on a large Continental or 350HP Lycoming. LOP airspeed is slower than ROP operations. You are burning less fuel but you are making less HP and therefore going slower. To save fuel fly higher (as long as there is favorable winds or winds are not too adverse). Otherwise PULL the throttle back (way back) and you will save way more fuel than all the monkey motions to get true LOP operations.
I don't think Lycoming is lying about finding more cylinder damage with lean operations. I agree if done carefully, with full engine instruments, LOP Ops can be safe. However the 2 jugs at 20F LOP with the other two near peak on the rich side does not sound good. That is why carbs should not operate LOP, the 50F EGT spread is too much. LOP needs all EGTs to be close.
Ambient play a big roll. Most of my flying anywhere requires MEAs above 9k or else I'll hit mountains within 30 minutes. Lean 'till the engine stops; you can't hurt it at 9 or higher. Yes, higher is key to economy. If you have to throttle the engine to get 75% or less you do get higher pumping losses and the airplane's draggier down lower.
I agree hitting a mountain is bad. Leaning till it stops is bad technique, but to each his own.
Pulling the throttle back a bit can be GOOD. It's common practice on carbed 182s because it does cause extra swirling, therefore better mixing and distribution. I've had a GEM in my 172 for 9 years. The effect is noticeable as stated, the rpm loss undetectable on the mechanical tach. The 172 has a detented mixture control. I would be able to better tune the mixture if it were a vernier, since the detents are either richer or leaner than I would like to set per the GEM. But a vernier control would require an STC (none exist) or 337. So much for the criticallity of mixture as viewed by Cessna and the FAA. The manual says lean till rough, enrich till smooth. Without a GEM and vernier you can't do otherwise.
Yes full instruments like GEM are great. However most C-172 are LUCKY to have one EGT, if that. I have about 150 hours in C-182's, most giving dual instruction. I did not know about this trick 15 years ago, so I never tried it. I was happy if the pilot checking out got the cowl flaps. I do know how to clear carb ice with a back fire in a C-182.
What does "ZERO wind conditions" have to do with running an engine? I think I get your drift in that you might want higher power when bucking a headwind. But I could really run with this one and start a thread about the dreaded downwind turn.
It has nothing to do with leaning; it has everything to do with flight planning. Winds aloft affect range and ground speed. (Yes I hope) From a pure performance stand point "zero winds" are used to compare performance (apples). No matter how efficient your airframe and engine is at high altitudes, when faced with 50 kt head winds at 8,500' and little winds down low, say at 2,000', you would be better flying at high power (not leaned) and lower altitude, terrain permitting. Right? (Tail wind fly slower, head wind fly faster) Using LOP operations means going slower and more exposure (time in) the head wind. You may have lower fuel flow with LOP but more fuel burn, miles per gal, for the trip and take longer. I never tried much LOP operations because none of the planes I have fly or have flown can do it. I would love to hear real actual numbers on fuel burn and speed at LOP and than ROP.
In sum, it is relative. Your engine may vary, and I think we've learned more in recent years than Lyc will admit. Get a GEM, fly high, use mogas!, and run LOP. Or ROP if that feels good; Mother Lycoming says it's all right.
I have a GRT EIS4000 engine monitor. I would never use MOGAS, it is only $1.00 less if you even can get it. To me that it is not worth it. Although that is a total different debate. However there have been so many accidents from autogas users I would not risk it.
I am not saying LOP is not good or can't work; I don't think Lycoming says that either, but everything has to be right (near perfect) to get the advantage, large engines (6 cylinders) have more to gain and carbs are just not able to produce fuel distribution that will allow consistent LOP operations. As far as damage from LOP, if done well, not a problem. If not done well it can cause grief. I am sure that is where Lycomings experience comes in. They know that in the field pilots may screw it up.
I have a O-360A1A and I am happy to throttle back to 2250 rpm (Hartzell limit)/ 20" map and back through town at 175 mph and 7.5 gal/hr. If I want to really fly slow and save gas, 20-squared, 168 mph @ 6.5 gal/hr. G
Here is a Avweb article I agree with on the subject:
http://www.avweb.com/news/reviews/182501-1.html