Dawley Aviation PIREP, or: Atlas is BACK

"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.

Matt Whiting wrote:

Done improperly LOP will start to melt exhaust systems. If you're
getting over 1500 EGT then you're not LOP, you're at peak. 75 LOP is
the same temp as 75 ROP.


Not the same.

It is precisely the same. 75 LOP is the same as 75 ROP. We are talking
EGT's not CHT's.


It is better as you have the same EGT with much lower CHTs.

Well yeah.

Jay,

If you only paid .62 AMU for your exhaust system rebuild then you got a
great deal!! Was this for a complete system or just the muffler and a
couple of pipes? We had to have our exhaust completely rebuilt last
annual (OI-360) from Dawley, but it cost us 1.8 AMU's. That was
replacing everything including one pipe that they couldn't "rebuild" and
we had to buy new from Mooney. The 1.8 AMU's we paid also included the
20% rip-off, er markup that our shop charges for the privilege of
letting them order parts for us. So in reality our system should have
cost 1.5 AMU's if we would have dealt with Dawley directly (which we
will from here on out), so if you go a complete system for .62 AMU then
my hat is off to you for procuring such a good deal!!

Jon Kraus
'79 Mooney 201
4443H @ TYQ

Jay Honeck wrote:
We were grounded last week, after discovering a cracked exhaust pipe and
rotted muffler baffles during routine maintenance.

Amazingly, we discovered that Dawley Aviation (*the* exhaust repair station
in the Midwest, and the place my A&P recommended) is located in Burlington,
WI -- literally on the road to Racine -- which was where we were headed for
"Xmas II". So, we ripped off the old system and tossed it in the back of
the Subaru with all the luggage and presents.

Four hours after leaving Iowa City, we were at Dawley's VERY impressive
offices. They are clearly a well-established business, with a large, clean
factory floor, and a nice, clean front office area, housing half a dozen
office workers in private offices. It looked more like a bank than any
aviation business I'd ever had the pleasure of seeing before -- quite
different from most of these kinds of places.

Steve, their VERY knowledgeable sales manager, was there to greet us. It
was obvious that he (and the staff) weren't used to having customers drop
stuff off (a steady stream of UPS and FedEx trucks flowed in and out while
we were there), but he took it all in stride and seemed genuinely pleased to
actually SEE someone for a change.

It turned out that Steve had trained with the same CFI as I did, over in
East Troy, Wi, so we were instantly fast friends as we traded "Old Bob"
stories back and forth. He took the cruddy old parts from me, identified
what could be re-used, and said that I could pick the new system up on our
way out of town the next day. It was as easy as that, and we were soon off
to Racine for Xmas with Mary's family.

The next day we swung back into their office, and it was all ready to go.
Dang, they literally replaced EVERYTHING except one flange on both the
triple pipes and the muffler. Everything else is brand-spanking new.

Steve wished Mary and the kids a happy new year, gave each of us a bag of
peanuts (which they apparently always throw in the box -- it's a Dawley
tradition that goes way back to their beginning), and charged us $620. Not
cheap, by any stretch, but still way cheaper than new.

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.)

My A&P put everything back together yesterday, and Atlas is now snug back in
his hangar, with a new exhaust, new oil/filter, new Iridium spark plugs, and
(hopefully) no more oil leak. Now all we need is some flying weather!

If you only paid .62 AMU for your exhaust system rebuild then you got a
great deal!!

Well, I didn't have to pay any shipping expense! :-)

Was this for a complete system or just the muffler and a couple of pipes?

It was for the three header pipes on the right side of the engine (as facing
forward) that come together into a single pipe, and the muffler/exhaust
pipe. The heat shroud was the only thing saved.

The left side header was still okay. That would have been another $390 or
so.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

"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.

Allen

"A. Smith" wrote in message
. net...

"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?

And expert on...what?

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.

Really? How?

"Matt Barrow" wrote in message
...
"A. Smith" wrote in message
. net...

"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?

And expert on...what?

An expert on repairing aircraft exhaust. Isn't that what Dawley does?

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.

Really? How?

I suggest that if you are really interested in this you get with Lycoming or
TCM and see what they suggest for your engine. There are only a handful of
engines that were designed to be ran LOP.

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

A. Smith wrote:

"Matt Barrow" wrote in message
...

"A. Smith" wrote in message
y.net...

"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?

And expert on...what?


An expert on repairing aircraft exhaust. Isn't that what Dawley does?

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.

Really? How?


I suggest that if you are really interested in this you get with Lycoming or
TCM and see what they suggest for your engine. There are only a handful of
engines that were designed to be ran LOP.

How do you design an engine to run LOP?


Matt

"Matt Whiting" wrote in message
...

How do you design an engine to run LOP?


Matt

Compression ratio, cumbustion chamber shape, valve placement, valve
material, crankshaft counterweight design...............................