Best Power or Best Economy

I had heard that Continental does not recommend flying @ best economy because the heat build-up is too great, I have a 20 with E-max and tried it without any adverse heat, any comments or suggestions?

Hi,

I think the best thing would be to have access to the member’s forum and its wealth of archived information about this exact topic by joining COPA. It’ll be the cheapest $50.00 you’ll ever spend.

Jeff

In reply to:


I had heard that Continental does not recommend flying @ best economy because the heat build-up is too great, I have a 20 with E-max and tried it without any adverse heat, any comments or suggestions?


Clayton: Jeff is correct, there is a wealth of info in the archives of the Member’s Forum, and I agree that membership is a terrific value. In fact, I think that you would find the answer to that question alone worth the price of membership. but to try to answer your question a little better:

  1. in order to operate safely LOP (or “best economy,” perhaps more accurately described as a range of more effecient engine operating parameters) you really need the Emax, or similar system, and a balanced “GAMI flow.” to find out more about that, I suggest you either join, or read John Deakin on “AvWeb” (http://www.avweb.com, I think).
    Assuming that your fuel air mixtures are relatively balanced from one cylinder to the next, there is no reason that your engine cannot operate Lean of Peak (LOP) safely. Most members of COPA seem to feal that operating LOP is not only significantly more efficient (read: uses less fuel), but it actually reduces heat and internal engine pressures and prolongs engine life.

Another outstanding source of information on this would be GAMI’s web site or Walter Atkinson, from the GAMI company (I think). I try to read John Deakins’ columns at least once a year as a refresher, and I can comfortably say that each time I re-read them, I learn something new. (I’m not sure what that says for me!) Lastly, and by far the best source for info on engine operation would be the “Advanced Pilot Seminars,” By George Braley and Walter Atkinson in ADA, ALabama. The latter is often affectionately called; the University of Ada. (I have not yet been, but I am optimistic that if I provide enough blatent plugs, I will be offered a discount!!!)

Why would TCM tell you not to operate LOP? Well there is a lot on that subject too on the members forum, but suffice it to say that a lot of their engines will not operate smoothly LOP.

Good luck.

Clayton:
Suffice it to say what Continental says on this subject is pure trash. Your engine runs COOLER at best economy so there is nothing that will burn up.
The suggestion to join COPA is a good one because hundreds of posts are devoted to this subject. You will learn a boat load of useful information and clear up all the myths.

Just to give you some specifics, in addition to the other (on the money) comments made here…

I strongly recommend that you read any/every article that John Deakin has written about engines for AVweb. Those are the articles titled “Pelican’s Perch”. The complete list of AVweb articles is http://www.avweb.com/news/columns/list.html>here.Pelican’s Perch #63.

But… read 'em all. His writing is about as clear and entertaining as any I’ve seen on something as technical as engine management.

  • Mike.

In reply to:


… wealth of archived information about this exact topic…


Certainly among the MOST DISCUSSED topics of the many things we talk about!

In reply to:


It’ll be the cheapest $50.00 you’ll ever spend.


Technically, it’ll cost just the same as any other $50.00… but oh, the VALUE! [:)]

  • Mike.

So far there is a consensus on the question I posted and it seems to be that I should join COPA…guess everyone’s a salesman…what a place to hang out and for only $50 bucks!

In reply to:


… “Advanced Pilot Seminars,” By George Braley and Walter Atkinson in ADA, ALabama.


Wow! Talk about your 1-in-a-gazillion, long-shot coincidences!
Just so happens that there’s another Advanced Pilot Seminarsalso run by a George Braley and a Walter Atkinson (and also a John Deakin)… also in a town called Ada… only this one’s in Oklahoma! [;)]

  • Mike.

In reply to:


So far there is a consensus on the question I posted and it seems to be that I should join COPA…guess everyone’s a salesman…what a place to hang out and for only $50 bucks!


For this particular question it is true that there is a huge amount of information and
discussion on the member’s forum, and distilling it down to a quick answer
over here really doesn’t do it justice. If you really want to read the collective thoughts
and experiences of people running their engine running their Cirruses from very rich,
to very, very lean, along with graphs, tables, suggestions and the now infamous
red fin, COPA is a very good place to go to find it.
As far as I am concerned, and from everything I have read and tried over the last few
years, running your engine lean of peak is much better for it than running it rich.
Moreover you have a plane where such operation is explicitly allowed by the POH
(below a certain power level) so you should feel pretty confident. Your experience,
that it runs cooler LOP than ROP is what should be expected, whatever the engine
manufacturer is reported to have said.

Hey buddy, give me 50 bucks and I’ll tell you everything you need to know [;)].

Don’t fall for it. I joined a while back and I’ve hardly learned anything from the 55,000 posts I’ve read. Well, I probably didn’t read more than 45,000 of them. Things I didn’t learn include flying techniques, weather, airframe icing, engine management, avionics, instrument approaches, satellite radio, NEXRAD in the cockpit, flying with kids and pets, flying to the Bahamas, flying in the mountains, hypoxia, oxygen systems and a bunch of other stuff that I forget I didn’t learn.

-Mike

P.S. May I be excused? My brain is full.

In reply to:


Your engine runs COOLER at best economy so there is nothing that will burn up.


I’m a Deakin fan too, but I think even he will agree that an engine runs hotter at “best economy” (defined by Continental and most other engine manufacturers as leaned to peak EGT) than it does at best power (usually defined as 100 degrees ROP).

You may be confusing “best economy” with LOP, which is indeed cooler (and more economical!) than “best economy.”

(The ultimate in LOP ops - the mixture fully closed - results in the best economy of all: a glider!)

D’Oh! Did I mess up the location of TCM and APS. My bad! (Sorry Walter, et al)

Morning All
For the left coasters, APS is scheduled for May 28-30
at Woodland Ca

Rick Langel
Commander 114

In my Cirrus at best economy, the CHT’s are cooler than at best power. By definition, the engine runs “harder” at best power and therefore runs hotter.
You may be confusing the EGT temps which are 100 degrees “cooler” than paek EGT while best economy is typically 50 degrees “coole” than paek. But it is not EGT that determines how hot the engine runs, it is CHT.

In reply to:


“best economy” (defined by Continental and most other engine manufacturers as leaned to peak EGT) than it does at best power (usually defined as 100 degrees ROP)!


On the SR22, the Continental / Emax Best Power setting is roughly 75ROP and the Best Economy Setting is roughly 40LOP. Running the SR22 engine at peak EGT at a high power setting - most would agree - isn’t a particularly good idea…

In reply to:


In my Cirrus at best economy, the CHT’s are cooler than at best power.


I agree that CHT is a better indicator of engine stress than EGT. I just don’t remember Deakin claiming that running at peak EGT results in lower CHT’s. Perhaps it does for some, but not in my experience.

Oops! I just went back and re-read some Deakin and, indeed, he claims a lower CHT at peak EGT than at 100 ROP, but with a difference that’s only barely discernable on his chart. The difference is probably measurable with an electronic engine monitor, but not with my old fashioned analog gauge (which only measures average CHT anyway, and that may be why I see higher CHT’s at “best economy” because some cylinders may not be there). [Late Edit: Someone pointed out off line that my analog CHT gauge measures only one cylinder, not the average of all cylinders. I was confusing it with the EGT gauge which is an average reading.]

So you are indeed correct in saying that “best economy” is no harder on the engine than 100 ROP. I stand corrected!

In reply to:


On the SR22, the Continental / Emax Best Power setting is roughly 75ROP and the Best Economy Setting is roughly 40LOP. Running the SR22 engine at peak EGT at a high power setting - most would agree - isn’t a particularly good idea…


Neither is running at 75 ROP, for that matter.

In reply to:


Neither is running at 75 ROP, for that matter.


I guess that depends on the altitude, no?

at 12k+, I will sometimes run 50-75 dROP there if I’m battling a head wind.

Jerry

In reply to:


I guess that depends on the altitude, no?


Yes. I should have qualified it to refer to power settings greater than 60% power.

Here’s the graph I use for the SR22. I stay out of the red.