Dawley Aviation PIREP, or: Atlas is BACK

"Matt Whiting" wrote in message
...
A. Smith wrote:
"Matt Barrow" wrote in message
...

Jay is merely parroting the OWT and misinformation that has been running
around out there for _years_.


Jay quotes an expert in the field and you accuse him of parroting
misinformation? LOP is good when properly done, but I think the
statement from Dawley says it is NOT being properly done for the most
part. The company I work for overhauls 400+ aircraft engines a year.
Our teardown shop can tell you which ones have been ran LOP and which
have not.

I think the point is that it is the temperatue seen by the exhaust pipe
that matters, not whether it is LOP or ROP. And the temps mentioned by
Mr. Dawley sound more like runnint at peak, rather than either side.
People seem to automatically blame running on the lead side and that
simply isn't supported by the data. It is an old wives tale pure and
simple.


Matt

Which is my point, people think they know how to run LOP but actually are
running at peak, causing damage. The guy at Dawley didn't say running LOP
did the damage, just that when the LOP operation began being pushed is when
the damage started showing up.

Allen

Matt Barrow wrote:

it has to be done quickly, like 3-4 seconds ("The
Big Pull" as Deakin describes it).

When flying with an engine equipped with their turbo-normalization system,
Tornado Alley recommends the pull from full rich to LOP take about 6
seconds.


--
Peter

"Peter R." wrote in message
...
Matt Barrow wrote:

it has to be done quickly, like 3-4 seconds ("The
Big Pull" as Deakin describes it).

When flying with an engine equipped with their turbo-normalization system,
Tornado Alley recommends the pull from full rich to LOP take about 6
seconds.

NO MORE THAN six seconds.


--
Matt
---------------------
Matthew W. Barrow
Site-Fill Homes, LLC.
Montrose, CO

(Incidentally, he said that the best thing that EVER happened to
their business was everyone running "lean of peak" and driving their EGTs up
above 1500 degrees. As temperatures approach 1600 degrees, the metal simply
starts to fail, and you end up saving pennies on gas, and blowing dollars on
exhaust systems.)

1600º is LOR (Lean of Rich) not LOP. 1600º is right at peak, as has been
stated. My engine typically peaks at 1590º. With the BMP (Big Mixture
Pull), I go from ROP through Peak to well LOP in about one second.
Yesterday on my flight I was running at 1490º, or 100º LOP. Now, if I
run it 100º ROP, what will my EGT read ?

BTW - my CHTs were 320º.
---
Ken Reed

1600º is LOR (Lean of Rich) not LOP. 1600º is right at peak, as has been

That's funny!

Jay Honeck wrote:

All in all, a very pleasant experience, and a real pleasure to work with a
guy that's so knowledgeable. In answer to questions, Steve went on at great
length about the metallurgy behind the work, and the reasons exhaust systems
fail. (Incidentally, he said that the best thing that EVER happened to
their business was everyone running "lean of peak" and driving their EGTs up
above 1500 degrees. As temperatures approach 1600 degrees, the metal simply
starts to fail, and you end up saving pennies on gas, and blowing dollars on
exhaust systems.)

That's funny as this isn't supported by the data the GAMI folks have
taken. It shows the EGTs being pretty much symmetrical about the peak.
So if you go lean of peak far enough you should be able to pretty much
equal the temps seen on the rich side of peak. And CHTs are actually
lower on the lean side so you should be saving your cylinder heads some
grief.

http://www.gami.com/frames.htm

Now if folks are running "at peak", then I see Steve's point, however,
"lean of peak" doesn't have to be problem if done properly.


Matt

"Matt Whiting" wrote in message
...
Jay Honeck wrote:

All in all, a very pleasant experience, and a real pleasure to work with
a guy that's so knowledgeable. In answer to questions, Steve went on at
great length about the metallurgy behind the work, and the reasons
exhaust systems fail. (Incidentally, he said that the best thing that
EVER happened to their business was everyone running "lean of peak" and
driving their EGTs up above 1500 degrees. As temperatures approach 1600
degrees, the metal simply starts to fail, and you end up saving pennies
on gas, and blowing dollars on exhaust systems.)

That's funny as this isn't supported by the data the GAMI folks have
taken. It shows the EGTs being pretty much symmetrical about the peak. So
if you go lean of peak far enough you should be able to pretty much equal
the temps seen on the rich side of peak. And CHTs are actually lower on
the lean side so you should be saving your cylinder heads some grief.

http://www.gami.com/frames.htm

Now if folks are running "at peak", then I see Steve's point, however,
"lean of peak" doesn't have to be problem if done properly.

Here's the summary:

http://www.avweb.com/news/columns/182084-1.html or, I you prefer, here's the
Printer Friendly version:

http://www.avweb.com/cgi-bin/udt/im....ry.id=1820 84

Read the graphs and charts.


--
Matt
---------------------
Matthew W. Barrow
Site-Fill Homes, LLC.
Montrose, CO

"Jay Honeck" wrote in message
news:ywRtf.692885$xm3.601961@attbi_s21...
All in all, a very pleasant experience, and a real pleasure to work with a
guy that's so knowledgeable. In answer to questions, Steve went on at
great length about the metallurgy behind the work, and the reasons exhaust
systems fail. (Incidentally, he said that the best thing that EVER
happened to their business was everyone running "lean of peak" and driving
their EGTs up above 1500 degrees. As temperatures approach 1600 degrees,
the metal simply starts to fail, and you end up saving pennies on gas, and
blowing dollars on exhaust systems.)

Yeah...he's really knowledgeable....on myths and legends.


--
Matt
---------------------
Matthew W. Barrow
Site-Fill Homes, LLC.
Montrose, CO

All in all, a very pleasant experience, and a real pleasure to work with
a guy that's so knowledgeable. In answer to questions, Steve went on at
great length about the metallurgy behind the work, and the reasons
exhaust systems fail. (Incidentally, he said that the best thing that
EVER happened to their business was everyone running "lean of peak" and
driving their EGTs up above 1500 degrees. As temperatures approach 1600
degrees, the metal simply starts to fail, and you end up saving pennies
on gas, and blowing dollars on exhaust systems.)

Yeah...he's really knowledgeable....on myths and legends.

Well, I suspect what he *means* is that people are leaning incorrectly in
attempting to run LOP, and/or they are trying to run LOP with carbureted
engines. Everyone is trying to save fuel nowadays, with avgas so high, and
people are simply cooking their exhausts systems in the process.

Steve has no reason to lie (in fact, he has every reason to say just the
opposite!) -- and, as sales manager of the largest exhaust shop in the
world, I suspect he has figured out where his customers are coming from.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

"Jay Honeck" wrote in message
news:bTZtf.694906$xm3.681484@attbi_s21...
All in all, a very pleasant experience, and a real pleasure to work with
a guy that's so knowledgeable. In answer to questions, Steve went on at
great length about the metallurgy behind the work, and the reasons
exhaust systems fail. (Incidentally, he said that the best thing that
EVER happened to their business was everyone running "lean of peak" and
driving their EGTs up above 1500 degrees. As temperatures approach 1600
degrees, the metal simply starts to fail, and you end up saving pennies
on gas, and blowing dollars on exhaust systems.)

Yeah...he's really knowledgeable....on myths and legends.

Well, I suspect what he *means* is that people are leaning incorrectly in
attempting to run LOP,

Well, you said "running", so it's still open...

OTOH, I wonder if he ever found out how much damage was done using the
techniques that (literally) "everyone" used in the past of running a few
degrees of peak. Remember that such was THE technique for years and years.

The problem is that people do two things wrong in GETTING to LOP; either
chickening out and staying near peak, or they make the transition from ROP
to LOP by taking several minutes while the engine is near peak.

Unless that's what he's talking about (I'm doubtful) I've seen nothing to
indicate he knows what the hell he's talking about.

and/or they are trying to run LOP with carbureted engines.

LOP with carburated engines is not a problem other than the likely roughness
that would cause kidney problems.


Everyone is trying to save fuel nowadays, with avgas so high, and people
are simply cooking their exhausts systems in the process.

And how would that differ from the late 70's?


Steve has no reason to lie (in fact, he has every reason to say just the
opposite!) -- and, as sales manager of the largest exhaust shop in the
world, I suspect he has figured out where his customers are coming from.

Didn't say he lied, I said he doesn't know what he's talking about. There's
a likely disconnect between an exhaust shop and expertise on engine
management. We've seen plenty that indicates the engines shops are just
parroting the myths and legends as well.