shdw

You have some slight miss information here. Instead of retyping what has already been done I will refer you and everyone else to this: The Savvy Aviator #59: EGT, CHT and Leaning

Enjoy.

rickair7777

Very interesting read. Basically says the manufacturers had it all wrong. I would do some more research before deviating from the POH in the ROP direction. I personally would not operate LOP without individual cyclinder EGTs.

shdw

First, of course I agree completely to operate successfully LOP you must have two things, GAMI injectors or any other precise fuel injectors and most importantly CHTs for each cylinder. That being said here is the other research you are looking for, I will stop at 3 links but the point is I have done plenty of research on this and LOP if you can do it is by far the way to go. I actually started a discussion on another forum about 6 months ago and spent days doing research on this for a course I am writing.


USA Best Economy

This gentlemen understands the economy of lean of peak, he doesn't realize that his CHTs are actually higher at ROP ops which I will show graphically in the next link. He says, "Trouble is, lean of peak can also result in cooler temperatures, along with reduced cylinder pressures. Braly and Roehl have spent the last 15 years fighting an uphill battle trying to prove that lean of peak is the way to go."


Lean of Peak

Take a look at the second two lines on the graph and note on the right side it points out that this section of the graph is for CHT. Now note the three vertical, left being ROP, center being peak, and right being LOP. You will see the CHTs on this graph confirm with that first link I posted for you. He also mentions, "I was pretty amazed at seeing that drop in temperatures occur. Make no mistake that heat is an enemy of any engine as is carbon buildup." This confirms the carbon build up I was referring to in a previous post, not addressing you but this topic in general.


General Aviation Modifications, Inc.

Finally, the most important link. This link goes into detail on operations lean of peak as well as what is needed and why it is needed. It also explains a bit of detail about the thousands of pilots and organizations that have been using this for years while others avoided it as taboo. It is nothing more than an old wives tail that miss informed pilots have been adamantly against for years, it is time that changes. The article also explains the increase in engine longevity from operations LOP.


I was unable to find the article, maybe someone here will have more luck, on FADEC systems and their leaning procedure, LOP.


On a final note, when you look for articles on this topic pay attention to the time the article was written. There are still many old articles floating around on the internet against LOP and/or for 50 ROP. Almost anything in the last few years, particularly the last year in regards to leaning procedures drastically pushes for and tries to explain away fallacies behind LOP operations.

I hope this satisfies your curiosity for further information on the topic and by no means was I attempting to sound like a smart ass in these posts, so I am sorry if I did. I think I am going to include this each time as I often find my tone doesn't come across right on these forums.

Ewfflyer

I'm in 100% agreement on LOP operations being done, but as mentioned above you also need to have those GAMI's, a good engine monitor, and of course appropriate training on how to do LOP ops'. I don't do LOP ops because the new aircraft I fly do not obviously come with the GAMI's, and plus a new engine IMO it doesn't hurt to keep it rich.

shdw

Just a heads up, if you have CHTs for each cylinder and the aircraft is new there wouldn't be any harm in attempting LOP operations and seeing the results. If the result is fairly even temperatures than your fine to operate LOP, as the third article explains the issue isn't running too lean, it is certain cylinders operating too rich and thus hotter than the pilot wishes. As long as you have the capability to monitor this you are fine, GAMI injectors are simply more precise and thus most likely to be able to operate LOP, but not a necessity. New injectors are much more precise than the injectors of 15 years ago when GAMI made its debut. Welcome to marketing lol.

Also LOP actually improves your engine life and each individual engine part, specifically the cylinders because it runs cooler CHTs than ROP. Unless you go to about 100 ROP as the original article I posted mentioned and the second article on post #2 with the graph confirmed your CHTs will be hotter. EGTs are simply put, a horrible system for monitoring internal engine temperatures.


Edit for detail: My apologies for the confusion first post, I was running on fumes when I wrote that and made it sound as though GAMIs are a must for this to work. In that third article it says, "have matched fuel injection nozzles" which any new system will posses. Furthermore, "I’ve had [oil-] fouled spark plugs, clogged fuel injectors, and magneto problems. But I’ve never had any engine problems associated with lean-of-peak." This gentlemen was not claiming, that I could see, to be using GAMIs.