ANNUAL, 2005 Redux...

[Denny]

The <dreaded> annual condition inspection time has arrived... Fat
Albert is currently perched upon the wing jacks pending gear swing
testing...
I have put 500 hours on the fat boy over the past three years and one
of the topics this year was the mags.... I had gone to the yellow
newspaper and priced the various Bendix magneto parts... Steve, the
mechanic, had the mags on the bench when I arrived... After looking at
the disassembled parts I got that familiar (to airplane owners) sinking
sensation (much like a big down draft on short final)... It was clearly
visible that the mags were in need of significantly more than points
and condensor... Bearing balls were significantly out of round, the
distributors were burned and pitted, one rotor had been rubbing on the
stator and was scarred, one coil had been arcing, etc...After spending
an hour (another $55 in labor) jawing about the mags, looking in
Steve's parts catalogs (going back to the Wright Bros.), and making
phone calls we came to several conclusions...
First, is that the mags needed total overhauls - actually more like a
sledgehammer massage...
Second, that two of the mags were a collection of random parts from
various fly-market magnetos, not all of which parts were from dash
numbers called for by Lycoming... One case was -30, one was missing
the tag, one was a -29, and one was a -11...
The plug wires are 4 years old and in fine shape... The cost of
Steve's time and parts to rebuild these mags was not economical... We
tossed around the idea of going to Slicks, but
that mean't buying new wires, which were not needed... In the end we
opted for a set of rebuilt mags from AVIAL by way of Aircraft Spruce...


First phone call to AS: I got a young male voice... Told him what I
needed, rattling off the 10 number... Got a long silence in return
followed by a plaintive request , 'did I know what page number in the
catalog that was on'... I advised him I wasn't looking at a catalog
and I suggested that he type 'magneto' into his computer screen
followed by the 10 number I gave him and see what turned up... Long
story short, after 5 agonizing minutes he finally located the magnetos
and announced that the -30 mags were special order only... At this
point it was clear he was in over his head and I did not believe
anything he said, told him I would think about it and hung up...

Second phone call: I counted to 20, slowly to allow Forrest Gump there
to be on the phone with someone else, and redialed AS... The bubbly,
blond, southern bimbo answers... I can smell the fresh nail polish
clear through the phone, as she is waving her hands to dry the gleaming
red lacquer.. The smooth southern drawl would make Dolly Parton
jealous..
I need some magnetos, I announce, with dread in my heart...
Bendix or Slick, y'all, she fires back...
This catches me off guard for a second... Bendix, I admit, stumbling
over my tongue..
Do you have the 10 number she asks... I rattle off the -29 one...
How many, she asks... Two, I admit...
Very good sir, those are the non impulse mags, they are in stock and we
can ship this afternoon... Do you need any impulse mags...
Jeez, this girl is giving me whiplash she's so quick... I rattle off
the -30 number and ask for two - holding my breath about the special
order schmozzle...
They are in stock and we can ship this afternoon... What else kin I hep
you with, sir...

At this point we had been engaged for roughly 90 seconds and I was
already thinking of asking her to marry me, but I suspected that my
wife would object... Instead we settled for my credit card number and
a promise that they would ship with the 6 o'clock untied parcel that
very day...
"Byeee, y'all have a good un.", she chirps and is gone...

The thing that annoys me about all this, $2,000 later, is that the
clapped out mags have been starting immediately and running like gang
busters... I can hardly wait to see how the new mags run...

denny

[Jon Woellhaf]

Denny wrote,

<very entertaining story snipped>

>I can hardly wait to see how the new mags run...

I think you already know what to expect. Keep us informed. Good luck!

Jon

[Montblack]

("Denny" wrote)
> The thing that annoys me about all this, $2,000 later, is that the clapped
> out mags have been starting immediately and running like gang busters... I
> can hardly wait to see how the new mags run...


How much $,$$$ was the Slick option?

Forgetting price: Slick vs. your option. What are the
advantages/disadvantages of the Slick system?


Montblack

[Jim Burns]

At least you'll be able to close your eyes and remember that sweet voice
each time you try to get them all timed correctly. Patience via
knowledgeable aircraft parts bimbo.... ahhhh.... gotta love it.

And just think... this year.... no carburetor problems (fingers crossed) and
no heater problems to deal with!!!

Good luck!

Jim
"It's not an airplane, it's an adventure!"

[RST Engineering]

Slicks are a little cheesier construction but the replacement costs of the
parts are a hell of a lot less expensive.

Jim



"Montblack" > wrote in message
...


>
> Forgetting price: Slick vs. your option. What are the
> advantages/disadvantages of the Slick system?
>
>
> Montblack

[JJS]

> The thing that annoys me about all this, $2,000 later, is that the
> clapped out mags have been starting immediately and running like gang
> busters... I can hardly wait to see how the new mags run...
>
> denny

That was a good write up, Denny. My problem with AS is that they don't list shipping charges or calculate them for
you on their website. I ordered a wingtip light bulb for the Cherokee a few days before Christmas. It cost around
$14.00. I knew shipping UPS or FEDEX would be very expensive so I chose USPS knowing that the Holidays would slow
down delivery. It arrived yesterday, so it took nearly two weeks. The shipping charge for the $14 light bulb was
$8.80. Their website offers a free catalog with free shipping and I ordered that as well. I wonder if they didn't
charge me shipping on both items?

Joe Schneider
8437R



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[Denny]

Montblack,
There is no operational advantage to one or the other... Both brands of
mags work... The Bendix mags are rebuildable to infinity and every
mechanic has parts on the shelf if you have a problem on the way to
Peoria... Not true of Slicks (at least yet)... Slicks are considered
to be a trade in item... You don't rebuild them in the field... My
Bendix cores will be massaged and wind up on someone elses airplane,
but for me it didn't make economic sense when I could buy the factory
rebuilt mag for less than the cost of the parts to overhaul...

Cheers ... Denny

[Denny]

That's true Jim... I am toasty warm and heven't even run the heater on
the highest setting yet. Subzero wx is comin so I will have the chance
I'm sure... The carb seems to be running just fine, now that we put
all the parts inside that the designer intended...

denny

[Denny]

ALL shipping has become expensive... I try to batch my orders so I hit
their minimum dollar amount for "free" shipping without going over the
weight limit... Not possible with the mags, so I got hit with the
freight charges for the weight... That's life I guess...

denny

[Denny]

Yeah, the thought of brand new Slicks was enticing but the numbers
didn't work out... Besides, these rebuilt Bendix mags will out live the
engines and the airplane by the time they are overhauled a few more
times...
There is no way of determining how many tens of thousands of hours are
on the carcasses we pulled out... The mechanic that owned the plane
for 43 years must have had fifty gallon drums of old magnetos that he
sifted through whenever he worked on them...
But, it was clear to me that without re-machining the bores and the
rotors, and completely replacing the internal parts ( though 3 of the
coils look good) that they could not be brought up to my standards with
a field IRAN... We also need to remember that Bendix parts and pieces
are on the shelf at almost every podunk airport if you have a
problem... That's a big plus...

denny

[Mike Spera]

I have been doing the "Slick Shuffle" for the past 12 years in my
Cherokee. At around 500 hours, I pull them off and physically take them
to the accessory overhauler 2 towns over. We usually put a new set of
points and condenser in one and replace the other. If I recall, there is
(or was) a $150 core or trade in credit that softened the blow. I
generally make a check out for $500 - $600 depending on whether the
impulse coupling mag is exchanged or the other one goes.

Mike
> How much $,$$$ was the Slick option?
>
> Forgetting price: Slick vs. your option. What are the
> advantages/disadvantages of the Slick system?
>
>
> Montblack

[NW_PILOT]

Denny, looks like you and I has similar annuals! This year both my mags
where replaced with new from aircraft spruce I went with slick conversion
kit after all core credits & rebates my total cost for Plugs, Mags & Harness
was about $1,025 + Labor


"Denny" > wrote in message
oups.com...
> The <dreaded> annual condition inspection time has arrived... Fat
> Albert is currently perched upon the wing jacks pending gear swing
> testing...
> I have put 500 hours on the fat boy over the past three years and one
> of the topics this year was the mags.... I had gone to the yellow
> newspaper and priced the various Bendix magneto parts... Steve, the
> mechanic, had the mags on the bench when I arrived... After looking at
> the disassembled parts I got that familiar (to airplane owners) sinking
> sensation (much like a big down draft on short final)... It was clearly
> visible that the mags were in need of significantly more than points
> and condensor... Bearing balls were significantly out of round, the
> distributors were burned and pitted, one rotor had been rubbing on the
> stator and was scarred, one coil had been arcing, etc...After spending
> an hour (another $55 in labor) jawing about the mags, looking in
> Steve's parts catalogs (going back to the Wright Bros.), and making
> phone calls we came to several conclusions...
> First, is that the mags needed total overhauls - actually more like a
> sledgehammer massage...
> Second, that two of the mags were a collection of random parts from
> various fly-market magnetos, not all of which parts were from dash
> numbers called for by Lycoming... One case was -30, one was missing
> the tag, one was a -29, and one was a -11...
> The plug wires are 4 years old and in fine shape... The cost of
> Steve's time and parts to rebuild these mags was not economical... We
> tossed around the idea of going to Slicks, but
> that mean't buying new wires, which were not needed... In the end we
> opted for a set of rebuilt mags from AVIAL by way of Aircraft Spruce...
>
>
> First phone call to AS: I got a young male voice... Told him what I
> needed, rattling off the 10 number... Got a long silence in return
> followed by a plaintive request , 'did I know what page number in the
> catalog that was on'... I advised him I wasn't looking at a catalog
> and I suggested that he type 'magneto' into his computer screen
> followed by the 10 number I gave him and see what turned up... Long
> story short, after 5 agonizing minutes he finally located the magnetos
> and announced that the -30 mags were special order only... At this
> point it was clear he was in over his head and I did not believe
> anything he said, told him I would think about it and hung up...
>
> Second phone call: I counted to 20, slowly to allow Forrest Gump there
> to be on the phone with someone else, and redialed AS... The bubbly,
> blond, southern bimbo answers... I can smell the fresh nail polish
> clear through the phone, as she is waving her hands to dry the gleaming
> red lacquer.. The smooth southern drawl would make Dolly Parton
> jealous..
> I need some magnetos, I announce, with dread in my heart...
> Bendix or Slick, y'all, she fires back...
> This catches me off guard for a second... Bendix, I admit, stumbling
> over my tongue..
> Do you have the 10 number she asks... I rattle off the -29 one...
> How many, she asks... Two, I admit...
> Very good sir, those are the non impulse mags, they are in stock and we
> can ship this afternoon... Do you need any impulse mags...
> Jeez, this girl is giving me whiplash she's so quick... I rattle off
> the -30 number and ask for two - holding my breath about the special
> order schmozzle...
> They are in stock and we can ship this afternoon... What else kin I hep
> you with, sir...
>
> At this point we had been engaged for roughly 90 seconds and I was
> already thinking of asking her to marry me, but I suspected that my
> wife would object... Instead we settled for my credit card number and
> a promise that they would ship with the 6 o'clock untied parcel that
> very day...
> "Byeee, y'all have a good un.", she chirps and is gone...
>
> The thing that annoys me about all this, $2,000 later, is that the
> clapped out mags have been starting immediately and running like gang
> busters... I can hardly wait to see how the new mags run...
>
> denny
>

[NW_PILOT]

> How much $,$$$ was the Slick option?
>
> Forgetting price: Slick vs. your option. What are the
> advantages/disadvantages of the Slick system?
>
>
> Montblack
>


I went with slick conversion kit on my 150 after all core credits & rebates
my total cost for Plugs, Mags & Harness was about $1,025 + Labor

[David Lesher]

"Denny" > writes:

>The plug wires are 4 years old and in fine shape... The cost of
>Steve's time and parts to rebuild these mags was not economical... We
>tossed around the idea of going to Slicks, but
>that mean't buying new wires, which were not needed... In the end we
>opted for a set of rebuilt mags from AVIAL by way of Aircraft Spruce...


These are the kind of GA stories that make me cry. Thirty five years
ago, I remember changing the points and rotor in a Beetle. That was
the last mechanical ignition I've seen.

I junked my 2nd Datsun 210 this year. From 1979 on, those two were
all I'd driven. And while I'd acquired and kept a spare ignition
module; I'd never used one. (Nor the spare starter....)

And while the Beetle was a PITA to start in cold damp weather with
a weak battery... my neighbor just donated away his +10yo Caddy
Coupe de Bismarck. After spending ~$10K on an engine rebuild a few
years ago {gag!} he finally gave up after the ?air? boost part of
the suspension failed & the dealer wanted $3K more to fix it. It
sat there for 2+ years because he really didn't want to let it go;
all the new ones (inc. his) were smaller and he kept hoping it could
be fixed...

Finally his spouse ordered it gone. The flatbed from the 501c3
couldn't hook it at the angle it was parked, so he and I used my
"battery boiler" charger and my welding cable jumpers. It fired up
on a squirt of ether; and as soon as the gas made it up front, kept
going. We managed to back it into the alley despite the fact he'd
left the parking brake on and the rear wheels were seized. (A little
dish soap & H2O helped...)

I keep hoping that someone somehow will figure out a way to move
some of the massive tecnology improvements we use (and ignore) daily
in our cars into the fleet; but I sure don't know what that route
is...


--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

[George Patterson]

David Lesher wrote:

> I keep hoping that someone somehow will figure out a way to move
> some of the massive tecnology improvements we use (and ignore) daily
> in our cars into the fleet; but I sure don't know what that route
> is...

Yeah. I heard an ad on the radio about a shop that had the gear to read the
computer chips for diagnosis in cars. That set me thinking about the diagnosis
technique frequently used with aircraft; replace parts until something works. It
seems to me that it wouldn't be hard to get the FAA to sign off on at least a
diagnostic chip.

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.

[Denny]

Uhh, seems like the number she quoted to me, was roughly $355 per mag
and $200 core deposit... I assume my cores will be accepted as they
were running on an engine when removed <but you know what 'assume' can
do>>> Even with the $800 back from cores, it's going to be $1600 or so
in the end with labor and shipping... Still, that's a 1200-1400 savings
over all new... Actually, I like Bendix mags.. Parts can be had
everywhere... And, I've been flying behind them for 60+ years...

Looks like there will be a delay in getting the ship back... I ordered
the mags at 4PM on Wednesday and they were in my hands at noon on
Friday... Not bad for UPS Brown from Ga to Mi...So, late Friday
afternoon I delivered them to Steve... While there Steve and I swung
the gear, and then I sat around and watched while he greased the wheel
bearings, reassembled the wheels and brakes, etc... Actually, he
dropped several hints that I could help if I wanted... Sittng there in
a white shirt and tie, I simply grinned and watched while he rolled his
260 pounds around on the floor like a beached whale... I did help get
it off the jacks...

Then he dropped the bomb... The FAA is going to be in the shop on
Monday, Tuesday, and Wednesday for his new Part 135 certification of
the books, the shop, the Chief pilot, and the Aztec... I informed
Steve that my airplane was NOT going to be in the shop for three days,
with the logs laying on the wing, while the FAA was prowling around
desperately looking for someone or something to violate... So, he WOULD
work Saturday and Sunday installing the mags, buttoning up the
inspection plates, dye checking the rudder hinges, test run, etc.,
etc., etc. and give my plane back to me so I could get it locked away
in a private hangar...

He about cried... Said it was going to take him all weekend to finish
all the squawks on the Aztec that miraculously showed up on the final
test flight by his Chief Pilot... After a bit of shouting and swearing,
he allowed that he could get Fat Albert out of the shop and into the
box hangar next door, which is not subject to the 135 inspection... I
was still growling like a Grizzly with a bad tooth, but it is the best
I can negotiate...

denny and Fat Albert

[Capt. Geoffrey Thorpe]

George Patterson" > wrote in message
news:ZK0wf.23428$uy3.5082@trnddc08...
> David Lesher wrote:
>
>> I keep hoping that someone somehow will figure out a way to move
>> some of the massive tecnology improvements we use (and ignore) daily
>> in our cars into the fleet; but I sure don't know what that route
>> is...

The technology got into cars because the government mandated fuel economy
and emission improvements. It shouldn't be hard to figure out what it will
take to get it into aircraft.
In any case, there are exactly two things "wrong" with aircraft engines. The
spark timing is fixed and the mixture control is in the hands of the pilot.
And you can't do anything about the first problem until you fix the second.

>
> Yeah. I heard an ad on the radio about a shop that had the gear to read
> the computer chips for diagnosis in cars. That set me thinking about the
> diagnosis technique frequently used with aircraft; replace parts until
> something works. It seems to me that it wouldn't be hard to get the FAA to
> sign off on at least a diagnostic chip.

Right. Now a mechanic just replaces parts until the fault codes go away...

It's nearly impossible to narrow things down to just one part, so even with
diagnostic codes to point the way, mechanics still tend to replace the easy
stuff first.
For example if you get a "oxygen sensor not switching" code, 9 times out of
10, the mechanic will replace the sensor. Then, only when that doesn't solve
the problem, will they will actually start to look for the cause of the
mixture problem (vacuum leak, etc.). Of course, there are those who will
just replace the sensor again. And again. And again... After a few tries,
they then complain that there is something wrong with the diagnostic
software.

FWIW, I write algorithms that do air fuel control and diagnostics at one of
the larger automobile manufacturers.

--
Geoff
the sea hawk at wow way d0t com
remove spaces and make the obvious substitutions to reply by mail
Spell checking is left as an excercise for the reader.

[[email protected]]

: In any case, there are exactly two things "wrong" with aircraft engines. The
: spark timing is fixed and the mixture control is in the hands of the pilot.
: And you can't do anything about the first problem until you fix the second.

The first is a compromise, but generally works really well for aircraft
engines... they *do* run at a constant RPM all the time. The second isn't that big of
a deal if the pilot is properly trained to use the mixture knob. Trouble is most
aren't because of the great degree of OWT and misinformation out there on the subject.

I would argue that the #1 biggest problem with aircraft engines is that they
are still air-cooled. Removing the tremendous thermal stresses of having 450 degree
CHT's make most of the "routine" aircraft engine problems go away. Stuck valves,
cracked exhaust flanges and cylinder heads, ridiculous octane requirements (100 for
8.5:1?) due to the heat and low RPM, galled cylinders/pistons due to overheating,
shock-cooling, and cold-starts, etc.

Liquid cooling stabilizes everything, lets more power be made more efficiently
with greater reliability. It doesn't even have to add too much weight.

-Cory

--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

[Capt. Geoffrey Thorpe]

> wrote in message
...
>: In any case, there are exactly two things "wrong" with aircraft engines.
>The
> : spark timing is fixed and the mixture control is in the hands of the
> pilot.
> : And you can't do anything about the first problem until you fix the
> second.
>
> The first is a compromise, but generally works really well for aircraft
> engines... they *do* run at a constant RPM all the time. The second isn't
> that big of
> a deal if the pilot is properly trained to use the mixture knob. Trouble
> is most
> aren't because of the great degree of OWT and misinformation out there on
> the subject.

Except that the optimal spark timing is a strong function of the air fuel
ratio. To get the full benifit of leaning, you need to change the spark. You
can't optimize the spark for the mixture if you don't know what the mixture
is.

> I would argue that the #1 biggest problem with aircraft engines is that
> they
> are still air-cooled.

Liquid cooling has it's advantages.

Removing the tremendous thermal stresses of having 450 degree
> CHT's make most of the "routine" aircraft engine problems go away. Stuck
> valves,
> cracked exhaust flanges and cylinder heads, ridiculous octane requirements
> (100 for
> 8.5:1?)

Octane requirement is a stong function of spark timing...
Of course, large, open combustion chambers with lower charge motion tend to
require higher octane too.

>due to the heat and low RPM, galled cylinders/pistons due to overheating,
> shock-cooling, and cold-starts, etc.
>
> Liquid cooling stabilizes everything, lets more power be made more
> efficiently
> with greater reliability. It doesn't even have to add too much weight.
>

Getting rid of points would be an improvement also. Solid state magneto's
are not hard to make.

--
Geoff
the sea hawk at wow way d0t com
remove spaces and make the obvious substitutions to reply by mail
Spell checking is left as an excercise for the reader.

[David Lesher]

"Capt. Geoffrey Thorpe" <The Sea Hawk at wow way d0t com> writes:

>>> I keep hoping that someone somehow will figure out a way to move
>>> some of the massive tecnology improvements we use (and ignore) daily
>>> in our cars into the fleet; but I sure don't know what that route
>>> is...

>The technology got into cars because the government mandated fuel economy
>and emission improvements. It shouldn't be hard to figure out what it will
>take to get it into aircraft.

Yes, this was the biggest push. But I believe once Detroit started
hiring EE's [they literally had ME's doing EE work for years...]
and got them into sync with the environment...[rotten power supply,
with 65V spikes seconds long, horrid temp & vibration issues, vicious
reliability demands, and oh, a NTE $0.25 price point...] they've NOW
gone a LONG way farther and continue to. That's because they have hungry
competitors who will not let them rest.

>In any case, there are exactly two things "wrong" with aircraft engines. The
>spark timing is fixed and the mixture control is in the hands of the pilot.
>And you can't do anything about the first problem until you fix the second.

Agreed. They need what cars have had for years: FADEC's with one
lever power control.

>FWIW, I write algorithms that do air fuel control and diagnostics at one of
>the larger automobile manufacturers.

Then you know far more about this than greasy-knuckle folks like moi.

--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

[David Lesher]

"Capt. Geoffrey Thorpe" <The Sea Hawk at wow way d0t com> writes:

>George Patterson" > wrote in message
>> Yeah. I heard an ad on the radio about a shop that had the gear to read
>> the computer chips for diagnosis in cars. That set me thinking about the
>> diagnosis technique frequently used with aircraft; replace parts until
>> something works. It seems to me that it wouldn't be hard to get the FAA to
>> sign off on at least a diagnostic chip.

>Right. Now a mechanic just replaces parts until the fault codes go away...

See my last rant...about alternators..

>It's nearly impossible to narrow things down to just one part, so even with
>diagnostic codes to point the way, mechanics still tend to replace the easy
>stuff first.
>For example if you get a "oxygen sensor not switching" code, 9 times out of
>10, the mechanic will replace the sensor. Then, only when that doesn't solve
>the problem, will they will actually start to look for the cause of the
>mixture problem (vacuum leak, etc.). Of course, there are those who will
>just replace the sensor again. And again. And again... After a few tries,
>they then complain that there is something wrong with the diagnostic
>software.

BT,DT,GtTS!

Thirty years ago a friend had a job teaching the folks at a certain
western Ohio weight measuring company how to fix their new load cell
scales. These guys had fixed huge mechanical scales for years and
were ....resistant... to change. Every time he got a board-swapper;
he'd put them on the rigged unit with ...intermittent.. backplane
wiring. They soon learned.

Good diags and error codes are tremendous timesavers, but they are
no substitute for a brain, logical thinking and a rigorous
problem-solving approach.

--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

[George Patterson]

Capt. Geoffrey Thorpe wrote:

> Right. Now a mechanic just replaces parts until the fault codes go away...

I've not found that to be the case. Not in the last 15 years, at least.

> It's nearly impossible to narrow things down to just one part, so even with
> diagnostic codes to point the way, mechanics still tend to replace the easy
> stuff first.
> For example if you get a "oxygen sensor not switching" code, 9 times out of
> 10, the mechanic will replace the sensor. Then, only when that doesn't solve
> the problem, will they will actually start to look for the cause of the
> mixture problem (vacuum leak, etc.).

The one time that showed up on my vehicle, they checked for (and found) a vacuum
leak first thing.

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.

[[email protected]]

Capt. Geoffrey Thorpe <The Sea Hawk at wow way d0t com> wrote:
: Except that the optimal spark timing is a strong function of the air fuel
: ratio. To get the full benifit of leaning, you need to change the spark. You
: can't optimize the spark for the mixture if you don't know what the mixture
: is.

Agreed. All I'm saying is that the for the aircraft application, the
operating regime (cruise) is a very small window of operating conditions. If it can
be optimized within that window, but made simultaneously safe to operate outside of
it, that'd be enough. I haven't thought it through completely, so they may be
mututally exclusive.

: Octane requirement is a stong function of spark timing...
: Of course, large, open combustion chambers with lower charge motion tend to
: require higher octane too.

Isn't it a stronger function of compression ratio and CHT, though? Timing
will help manipulate the time at which the peak pressure occurs, but the detonation
margin has very little to do with timing.

: Getting rid of points would be an improvement also. Solid state magneto's
: are not hard to make.

Agreed. Points suck. Making them lightning-robust might take some
thought, however... :)

All of these things (solid-state "points," variable timing intelligently
dependent on RPM and manifold pressure, etc) would be very difficult to accomplish
mechanically to aviation robustness standards. Computers like FADEC would make it
easier to implement, but still quite difficult to certify.

-Cory


--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

[Aaron Coolidge]

Capt. Geoffrey Thorpe <The Sea Hawk at wow way d0t com> wrote:
: In any case, there are exactly two things "wrong" with aircraft engines. The
: spark timing is fixed and the mixture control is in the hands of the pilot.
: And you can't do anything about the first problem until you fix the second.

You are spot-on. I would argue, though, that you can't fix the second
problem until you eliminate the first.
--
Aaron C.

[Denny]

The magnetos we pulled off Fat Albert date back further than we can
trace... They have been overhauled, rebuilt, massaged, tinkered, and
cobbled for 48 years... And they will go back to AVIAL who will strip
them down, regrind the bearing surfaces, replace the bushings,
remagnetize the rotors, replace the internal small parts, paint them
shiny black, and they will go fly another 20 years on someones'
motor... Tough to do that with microelectronics...

I've had outboard motors with transistorized, CD, ignition... The
ignition was a constant source of problems and sudden failures... On
an airplane I want a magneto to back up the electronic ignition, just
in case on a dark and stormy night...

denny - older than dirt

[[email protected]]

On 9-Jan-2006, Aaron Coolidge > wrote:

> Capt. Geoffrey Thorpe <The Sea Hawk at wow way d0t com> wrote:
> : In any case, there are exactly two things "wrong" with aircraft engines.
> The spark timing is fixed and the mixture control is in the hands of the
> pilot.
> : And you can't do anything about the first problem until you fix the
> second.
>
> You are spot-on. I would argue, though, that you can't fix the second
> problem until you eliminate the first.


And after we resolve the magneto/mixture knob vs. electronic
ignition/automatic mixture control issues we can discuss the fact that here,
in the year 2006, manufacturers are still making aircraft engines with
CARBURETORS! And the "advanced" engines have MECHANICAL (rather than
electronic) fuel injection!

Still, in terms of reliability and durability piston aircraft engines score
pretty well. How long would a typical Detroit V6 engine last if it was
called upon to deliver full rated power for several minutes a few times a
day, and 75% of full rated power for several hours at a stretch?
--
-Elliott Drucker

[Denny]

Well, Steve survived his Part 135 review and is now a full fledged for
hire air carrier...
So, today when I bopped in (after driving half the length of the state
- gawd I hate driving) I found him replacing the rear wall of the
baggage compartment on Fat Albert after he <apparently> inspected the
cables to the tail planes, tested the ELT, etc...
We pulled all the other planes out of the hangar, including his
newly-135 Aztec, and proceeded to fire up Fat Albert's engines for the
first time with the new mags... Gee, they even ran... Mag drops are 100
on the left mag and 125 on the right mag... Same on both engines...
Adjusted the idle and it looks like I will get the fat boy back on
Friday (ceilings indefinite with 1/2 mile viz at this time) after they
button things up...

denny

[Eduardo K.]

In article <Lk0xf.5150$sa4.3381@trnddc07>,
> wrote:
>
>
>Still, in terms of reliability and durability piston aircraft engines score
>pretty well. How long would a typical Detroit V6 engine last if it was
>called upon to deliver full rated power for several minutes a few times a
>day, and 75% of full rated power for several hours at a stretch?

an 6 liter automotive V8 can make 200hp all day long...

--
Eduardo K. | Some say it's forgive and forget.
http://www.carfun.cl | I say forget about forgiving just accept.
http://e.nn.cl | And get the hell out of town.
| Minnie Driver, Grosse Point Blank

[Matt Whiting]

Eduardo K. wrote:
> In article <Lk0xf.5150$sa4.3381@trnddc07>,
> > wrote:
>
>>
>>Still, in terms of reliability and durability piston aircraft engines score
>>pretty well. How long would a typical Detroit V6 engine last if it was
>>called upon to deliver full rated power for several minutes a few times a
>>day, and 75% of full rated power for several hours at a stretch?
>
>
> an 6 liter automotive V8 can make 200hp all day long...
>

And what is the maximum HP of this engine that you have in mind?

Matt

[Aaron Coolidge]

Eduardo K. > wrote:
: In article <Lk0xf.5150$sa4.3381@trnddc07>,
: > wrote:
:>
:>
:>Still, in terms of reliability and durability piston aircraft engines score
:>pretty well. How long would a typical Detroit V6 engine last if it was
:>called upon to deliver full rated power for several minutes a few times a
:>day, and 75% of full rated power for several hours at a stretch?

: an 6 liter automotive V8 can make 200hp all day long...

A 6-liter IO-360 can make 200 HP all day long as well.
--
Aaron C.

[George Patterson]

Aaron Coolidge wrote:

> A 6-liter IO-360 can make 200 HP all day long as well.

Really? What engine is that? Lycoming's 6 liter engines are rated at 180 hp
(some less than that), and it's generally considered a bad idea to try to run
one at 100% for long periods of time.

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.

[nrp]

In defense of aircraft engines, the 6 L car engine has to do 200 hp at
2700 RPM & go thru a weight reduction program so severe that it ends up
being aircooled with no thermal inertia. Then it has to have its
design frozen by certification by the bureaucracy after which it is
second guessed by a ruthless legal system. Then its users expect it to
last 2000 hrs at say 70% power.

Then for some reason, only a few engines get built since the demand is
so low.

[George Patterson]

nrp wrote:
> In defense of aircraft engines, the 6 L car engine has to do 200 hp at
> 2700 RPM & go thru a weight reduction program so severe that it ends up
> being aircooled with no thermal inertia.

And, in fact, that 6 liter car engine probably won't put out 200 hp at 2700 rpm.
Slow an auto engine down that much, and it usually puts out about 60% of it's
claimed maximum power. Or you can add reduction gearing that also robs power. So
you're really looking for a 6 liter auto engine that puts out about 330 hp.

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.

[Aaron Coolidge]

George Patterson > wrote:
: Aaron Coolidge wrote:

:> A 6-liter IO-360 can make 200 HP all day long as well.

: Really? What engine is that? Lycoming's 6 liter engines are rated at 180 hp
: (some less than that), and it's generally considered a bad idea to try to run
: one at 100% for long periods of time.

IO-360-A3B6D in a Mooney 201, among many others. Lyc claims their engines
can be run at 100% power continuously in the TCDS. See TCDS 1E10, first page.
"Max Continuous Horsepower/RPM full throttle at Sea Level pressure altitude:
200-2700".

The HIO-360-C1A (among others) is rated 205HP @ 2900 RPM continuously

--
Aaron C.

[Newps]

>
> :> A 6-liter IO-360 can make 200 HP all day long as well.

No such thing as a 6 liter IO-360.

[Aaron Coolidge]

Newps > wrote:



:>
:> :> A 6-liter IO-360 can make 200 HP all day long as well.

: No such thing as a 6 liter IO-360.

OK, you got me: 5.88295598 liter IO-360, which is actually 359 cubic inches.
Kind of like Ford's "5.0" liter 302 V8, which is actually 4.94889333 liters.
Or, are you objecting to "liter" instead of "litre"? I actually prefer
"litre", but the USA spelling is supposed to be "liter". If I use "litre"
I will have to start using "aeroplane" as well, I suppose...
--
Aaron C.

[Eduardo K.]

In article >,
Matt Whiting > wrote:
>Eduardo K. wrote:
>>
>> an 6 liter automotive V8 can make 200hp all day long...
>>
>
>And what is the maximum HP of this engine that you have in mind?
>

300? 350?

thing is, aircraft engines are actually good and so are automotive
engines... the difference in advertised power is just that aircraft
engines are designed to be run at 75% power all day long and car
engines for short peaks of a very high number....

just different design objectives.



--
Eduardo K. |
http://www.carfun.cl | "World domination, now"
http://e.nn.cl | Linus Torvalds

[nobody]

Speaking of being toasty warm, the last trip I made in my Aztec was at the
first
of January at night with the OAT around 20 degs F. The heater was not
working.
After a 6 hour round trip in that, even with heavy clothes, jackets, gloves
and blankets,
we were miserable. It is hard to tune the radios with ski gloves, so my
right hand was in
and out of the glove a lot, and the result was numb fingers.

That finally provided the motivation needed to get the heater working. It
is a Southwind
Model 940DB12, which is rated at 15,500 BTU/hr on low and 27,500 BTU/hr on
high. I used to wonder if it were even capable of keeping the cabin warm,
but after
looking at my old thermo book and doing a little calculation, I determined
that if a heater
that size can't keep the Aztec cabin warm, something is really, bad wrong.

Anyway, after studying the service manual on the heater for a while to
understand how it
was supposed to worked and doing a little trouble shooting, it was revealed
that the heater
overhaul shop had incorrectly wired the heater. I don't know how it ever
passed a burn
test. I'll bet it didn't. It would light from the prime fuel charge, open
both fuel
values, burn very rich and smoke migthly until the high temperature
thermostat opened which
closed both fuel values. Only the high heat fuel value was suppoed to be
controlled
by the thermostat. Controlling both fuel values with the thermostat caused
combustion
to stop once the heater exceeded the 240 deg F outlet temperature. Once the
flame was
out, the heater had to be turned off, allowed to cool, and reprimed before
it would ignite again.

It was supposed to ignite, burn on low, and only open the second fuel value
if the operator
selected high heat. In high heat, the increased fuel flow requires
additional combustion air
for the proper mixture. Proper combustion airflow depends on an increased
pressure head
from the slipstream. The airplane needs to be flying to provide this 1" to
2" of water pressure
head in the intake. There is a very small ram air scoop on the air intake
for this purpose, which
has been "calibrated" with a couple of small holes drilled into the flage,
at least I'm guessing that what
the small holes are for. This is why the airplane's Approved Flight Manual
advices against using
high heat during ground operatiions and cautions that doing so will result
in excessive smoking
from the heater exhaust.

Once it was wired to match the wiring diagram in the service manual, it
works like a champ.
We have heat!!!!!!!

I'm still thankful for you guys educating me about C&D and I will use them
for
parts and/or a rebuilt should the old Southwind hang it up, but for now, it
is going
strong. Now I need to add a CO detector in the cabin to warn is the heat
exchanger
springs a leak.

I also need to get motivated to relace the side windows like. I need Jim
Burns for
my partner :-)

Ronnie


"Denny" > wrote in message
oups.com...
> That's true Jim... I am toasty warm and heven't even run the heater on
> the highest setting yet. Subzero wx is comin so I will have the chance
> I'm sure... The carb seems to be running just fine, now that we put
> all the parts inside that the designer intended...
>
> denny
>
>

[Jim Burns]

> We have heat!!!!!!!

Congrats!! ;) Although we have a Janitrol, both heaters are fairly simple,
it just takes some patience to figure out what's going on. Am I remembering
correctly that you are in TX? There's also a well known heater shop in
Dothan AL, http://www.haroldhaskinsinc.com/pages/1/index.htm

> I also need to get motivated to relace the side windows like. I need Jim
> Burns for
> my partner :-)

The side windows are easy and you can trim them to fit with a belt sander.
Just clean everything up real good before installing so you get a good bond
if you use silicone. Clean up the excess while it's wet, you'll never get
it off without damage if you let it dry. You can also use the original black
window seal goo. We bought LP Aero windows, 1/4 which required a 337, or
you can go with 3/16 or 1/8" and thermopanes from Great Lakes without a 337.

Jim

[nobody]

Yes, I'm Austin, TX.

Matter of fact, I didn't want to mention any names, but since you
brought it up, that heater shop in Dothan, AL is the one who's
sticker is on the heater and who's signature is in the log books
as having done the last overhaul. Hopefully their work on testing
the heat exchanger for leaks was better than their work on the wiring.
Maybe the tech who did the wiring was having a bad hair day.
Everybody makes mistakes, but I would have expected those errors
to be caught during the burn and post installation test. But who knows,
maybe the heater left their shop propely wired and adjusted and the
mechanic in the field who reinstalled the heater decided he needed to
move a few wires around to make it work better.

I saved your original post about installing the side windows. I need to
tack that project. One of our windows has a crack in the inside pane.
Maybe when the weather gets too bad to fly here in Texas, I'll tackle that
project :-)

Ronnie

"Jim Burns" > wrote in message
...
>> We have heat!!!!!!!
>
> Congrats!! ;) Although we have a Janitrol, both heaters are fairly
> simple,
> it just takes some patience to figure out what's going on. Am I
> remembering
> correctly that you are in TX? There's also a well known heater shop in
> Dothan AL, http://www.haroldhaskinsinc.com/pages/1/index.htm
>
>> I also need to get motivated to relace the side windows like. I need Jim
>> Burns for
>> my partner :-)
>
> The side windows are easy and you can trim them to fit with a belt sander.
> Just clean everything up real good before installing so you get a good
> bond
> if you use silicone. Clean up the excess while it's wet, you'll never get
> it off without damage if you let it dry. You can also use the original
> black
> window seal goo. We bought LP Aero windows, 1/4 which required a 337, or
> you can go with 3/16 or 1/8" and thermopanes from Great Lakes without a
> 337.
>
> Jim
>
>

[Jim Burns]

Hey Ronnie,
I've only bought a few parts from Haskins, so I can't comment on their
repair work, but in your case it obviously wasn't done correctly, and if
they did burn test it, I agree with you, it wasn't for long enough! Our
Janitrol is some what simpler in it's operation than the Southwind, it's
either on or off, no high speed/low speed, rather it's controlled by an
adjustable thermostat. The wiring on ours is also rather simple and easy to
understand, if ours was wired incorrectly, it would never ignite at all.
My aerial applicator friend that also owns an Aztec, has all the leak
testing equipment and sealing bulbs so thankfully I am able to get ours
tested locally and without pulling it from the plane.

Jump right into that window project! :) It will make your entire airplane
look 20 years younger! We had them put a slight grey tint in our side
windows that adds some contrast against the white paint, making it look
pretty sharp.

Jim

"nobody" > wrote in message
. com...
> Yes, I'm Austin, TX.
>
> Matter of fact, I didn't want to mention any names, but since you
> brought it up, that heater shop in Dothan, AL is the one who's
> sticker is on the heater and who's signature is in the log books
> as having done the last overhaul. Hopefully their work on testing
> the heat exchanger for leaks was better than their work on the wiring.
> Maybe the tech who did the wiring was having a bad hair day.
> Everybody makes mistakes, but I would have expected those errors
> to be caught during the burn and post installation test. But who knows,
> maybe the heater left their shop propely wired and adjusted and the
> mechanic in the field who reinstalled the heater decided he needed to
> move a few wires around to make it work better.
>
> I saved your original post about installing the side windows. I need to
> tack that project. One of our windows has a crack in the inside pane.
> Maybe when the weather gets too bad to fly here in Texas, I'll tackle that
> project :-)
>
> Ronnie
>
> "Jim Burns" > wrote in message
> ...
> >> We have heat!!!!!!!
> >
> > Congrats!! ;) Although we have a Janitrol, both heaters are fairly
> > simple,
> > it just takes some patience to figure out what's going on. Am I
> > remembering
> > correctly that you are in TX? There's also a well known heater shop in
> > Dothan AL, http://www.haroldhaskinsinc.com/pages/1/index.htm
> >
> >> I also need to get motivated to relace the side windows like. I need
Jim
> >> Burns for
> >> my partner :-)
> >
> > The side windows are easy and you can trim them to fit with a belt
sander.
> > Just clean everything up real good before installing so you get a good
> > bond
> > if you use silicone. Clean up the excess while it's wet, you'll never
get
> > it off without damage if you let it dry. You can also use the original
> > black
> > window seal goo. We bought LP Aero windows, 1/4 which required a 337,
or
> > you can go with 3/16 or 1/8" and thermopanes from Great Lakes without a
> > 337.
> >
> > Jim
> >
> >
>
>

[Denny]

Don't remember if I gave the ending to the group... The rebuilt mags
went on without problems and the engines started promptly... I have
flown 10+ hours at this point and have no complaints about the mags
(didn't have complaints before)... I did have one fouled plug on the
3rd flight (leaded crap ought to be outlawed) that cleared with the ol
full throttle with lean mixture trick, but the tanks have been pretty
well flushed of lead now by topping off with the cheapest, nastiest,
mogas I can find... The engines running smooth and loving every drop of
it...
Total bill was $3200 parts and labor for the annual, lots better than
the $12K+ last year... Sooner or later I'm going to get an annual for
just his shop rate (yeah, right!>, cept I did notice some oil on the
bottom plugs on 2 cylinders on the starboard engine <sigh>, so I can
see an overhaul in my future... I'm busily collecting new cylinders
and overhaul parts...

denny and Fat Albert the Apache