View Full Version : Book Review:Maintenance/overhaul guide to Lycoming aircraft engines, Christy
Paul
December 22nd 04, 02:20 AM
Not a substitute for the Overhaul manual
This book contains an overview of maintenance and overhaul for the
WWII-era-technology air-cooled Lycoming engines which unfortunately
still power the vast majority of personal aircraft in the world. It is
useful to people who have worked on other engines, to provide an
overview of the procedures and tooling needed, but it contains little
information not in the Lycoming or military manuals, which are
available at reasonable cost in reprint form from suppliers in addition
to the extremely expensive one from the folks at 652 Oliver Street.
You will need to have the factory book with the most recent Table of
Limits if you are working on this as a certificated aircraft engine. If
you are using it as an experimental or airboat powerplant (are you sure
you really want one of these overpriced museum pieces??) it's not
necessary but can't be urged strongly enough because the first 'oops'
will cost you a lot of money.
Joe Christy was a good writer who turned out a lot of TAB-G/L books,
apparently for beer money, but he has been deceased-he lived to a
considerable age-for several years now. So there are things that aren't
covered in this book he probably would have. But by and large the
Lycoming is still the same engine it was at the beginning of the
postwar lightplane boom, and so this book is just as useful as it ever
was-okay supplemental reading or for the armchair mechanic, but not the
definitive (if dense) factory manual.
alexy
December 22nd 04, 05:55 AM
"Paul" > wrote:
>This book contains an overview of maintenance and overhaul for the
>WWII-era-technology air-cooled Lycoming engines which unfortunately
>still power the vast majority of personal aircraft in the world.
Why, and for whom, is that unfortunate?
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.
Denny
December 22nd 04, 01:04 PM
Paul, your unfortunate derision of Lycoming (and I assume Continental
also) engines shows your bias and your lack of knowledge... There are
actual, real world reasons why the certificated engines you deride
continue to be the engines of choice of the manufacturers of
certificated aircraft...
Denny
alexy
December 22nd 04, 04:14 PM
Gene Kearns > wrote:
>This is typical "engineer" mentality.
I'd guess what you describe below to be a marketing mentality rather
than an engineering one.
>
>If a product can be made more complex, or if it can be squeezed for
>one more 1/2% of power, or if it could be installed in a smaller space
>or made smaller somehow, or if it could run off of some boutique fuel,
>it would absolutely obsolete everything coming before, regardless of
>the original product's history.
Whether engineering or marketing driven, isn't a push for continual
improvement, even to the point of occasional failures like you point
out due to "overpushing", not desirable?
>Some of these engines may not be that far from a 1937 tractor engine,
>but, you know what? 65+ years later, we still haven't found anything
>affordable and reliable enough to replace them.... AND if they were
>sold for what they were *worth* they probably sell for less than $1000
>per cylinder, new..... but that is another story....
I guess "worth" is subjective. They are worth far more than that to a
lot of pilots who fly behind them. And if pilots suddenly decided that
they would only pay $1,000 per cylinder, I wonder if any would be
made? I suspect that the increased market at that price would be small
enough that they could never get the economies of scale to manufacture
for that price.
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.
alexy
December 22nd 04, 09:56 PM
Gene Kearns > wrote:
>On Wed, 22 Dec 2004 11:14:50 -0500, alexy > wrote:
>>>Some of these engines may not be that far from a 1937 tractor engine,
>>>but, you know what? 65+ years later, we still haven't found anything
>>>affordable and reliable enough to replace them.... AND if they were
>>>sold for what they were *worth* they probably sell for less than $1000
>>>per cylinder, new..... but that is another story....
>>
>>I guess "worth" is subjective. They are worth far more than that to a
>>lot of pilots who fly behind them. And if pilots suddenly decided that
>>they would only pay $1,000 per cylinder, I wonder if any would be
>>made? I suspect that the increased market at that price would be small
>>enough that they could never get the economies of scale to manufacture
>>for that price.
>
>Then by the same logic, that 8 cylinder engine in your automobile is
>"worth" $40,000+.
I don't see how that is the same logic. People are willing to pay
$20k+ for a 4-cyliner aircraft engine, but I doubt if any of them
would be willing to pay $40k for an 8-cylinder auto engine. So for
them, the aircraft engine is worth $5k+ per cylinder, while the auto
engine is not.
How do you define "worth"?
>It is hard to make the economy of scale argument
>and the "these things haven't changed in 50 years" argument at the
>same time. The second year you go into production you have your
>tooling and a track record.
First, I wouldn't make the "these things haven't changed in 50 years"
argument. No question that the changes haven't been as dramatic as in
other engines based on this Pre-WWII technology (the internal
combustion engine), but it's a matter of degree.
Secondly, if the tooling for the annual production of 100,000 units of
product x were just 500 copies of the tooling for producing 200 units
per year, this argument would have merit. But I am not aware of any
manufacturing processes that work that way.
>
>If we forget that these are aircraft engines and just look at the fact
>that they are machined castings and forgings.... there is no way we
>can justify the astronomical price tags....
Well, there is liability insurance, testing, and above all, the law of
supply and demand.
1) People are willing to pay those prices,
2) companies making these products have assessed the market and
determined that lowering prices would not sell enough additional units
to increase profits
3) companies with the engineering and manufacturing expertise to
create competitive products have for the most part decided that they
can't produce them inexpensively enough to attract enough market share
to make a profit, and
4) the few companies who have tried to enter the market with
competitive products have proven the others in point 3 right.
What kind of "justification" do you have in mind? By all means, if you
can make a profit building and selling them for less, put together a
business plan and go talk to venture capitalists! <g>
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.
Denny
December 22nd 04, 11:52 PM
The manufacturers of certificated aircraft pay LyCon prices because the
only alternative until very recently was an Allison or P&W turboprop at
ten times the cost. I'm not sure any of the other supposedly
certificated engines being talked of are 1) actually certificated in
the U.S, and 2) actually shipping. The Zoche and DynaCam were thinly
veiled efforts to pimp up some venture capital; neither had any real
desire to produce engines.
Homebuilders use these same engines because most homebuilders today
just want to fly and are "building" as a dodge around type
certification: most lack fabrication skills or any desire to
experiment. Look at Richard Van Grunsven, who is making a lot of money
on the RV kits. If people will pay those prices for sheet aluminum
and assorted widgets why should he get his airplane certificated and
tool up and manufacture them? His margins are as high as a certificated
lightplane, he is making a lot of money with relatively little work.
If the Lycoming or Continental engine were really more reliable than
commodity general purpose engines, they'd be used in many other
applications. They are 1930s designs that if not protected by
certification would have been out of production for decades. General
purpose production engines have been installed in aircraft, usually by
people with a lack of resources in manufacturing and design, and yet
flown pretty well. If a company like Mercury Marine chose to get
involved in powerplants for experimental aircraft, they could put
Lycoming out of that market segment in a couple of years.
Denny
December 23rd 04, 12:06 AM
From: Gene Kearns >
Date: Wed, 22 Dec 2004 10:07:18 -0500
Local: Wed, Dec 22 2004 7:07=A0am
Subject: Re: Book Review:Maintenance/overhaul guide to
This is typical "engineer" mentality.
>>If a product can be made more complex, or if it can be squeezed for
one more 1/2% of power, or if it could be installed in a smaller space
or made smaller somehow, or if it could run off of some boutique fuel,
it would absolutely obsolete everything coming before, regardless of
the original product's history.
>>There are enough engineering failures to underscore this mind set.
I'll give you two..... Continental's Tiara engine and Lycoming's
experience with the GSIO-720-A1A.
>>Some of these engines may not be that far from a 1937 tractor engine,
but, you know what? 65+ years later, we still haven't found anything
affordable and reliable enough to replace them.... AND if they were
sold for what they were *worth* they probably sell for less than $1000
per cylinder, new..... but that is another story....
The Continental Tiara was an example of ignoring the published
literature. Any gear designer could tell them that 2:1 is the worst
ratio because the same teeth see each other every other rev. It's in
all the books. They tried to use the cam gear as a reduction gear, a
stupid idea.
I have no experience with geared 720s but I remember well the TIGO-541
and the GSIO-480, both of which were marvels of trouble. The 480 had
an oddball mechanical injection system used nowhere else.
If Lycoming or Continental had to make their ridiculous contraptions
work in anything except an airplane, they would probably quit and go
home. No one ever mentions that the reason the O-290-G engines were
available cheaply until modern times is that they were an absolute pain
in the ass in their original homes. Continental was smarter than to
try to sell the IOL-550 as a sport boating engine, even though many
custom Chevys sold for as much as the Continental did in aircraft trim.
Twenty years of ski and fishing boat experience have convinced me that
given a professionally engineered reduction drive a Chevy or Ford V8 is
a lot more reliable than any engine with bolt on cylinders and a split
crankcase.
Denny
December 23rd 04, 01:12 AM
From: Richard Riley >
Date: Wed, 22 Dec 2004 16:52:54 -0800
Local: Wed, Dec 22 2004 4:52 pm
Subject: Re: Book Review:Maintenance/overhaul guide to Lycoming
aircraft engines, Christy
On 22 Dec 2004 15:52:35 -0800, "Denny" > wrote:
:
If the Lycoming or Continental engine were really more reliable than
:commodity general purpose engines, they'd be used in many other
:applications. They are 1930s designs that if not protected by
:certification would have been out of production for decades. General
:purpose production engines have been installed in aircraft, usually by
:people with a lack of resources in manufacturing and design, and yet
:flown pretty well. If a company like Mercury Marine chose to get
:involved in powerplants for experimental aircraft, they could put
:Lycoming out of that market segment in a couple of years
..
How about a car company? I mean, if a company that produced high
performance automotive engines got into the business, they'd own it,
right? Especially if they had experience with air cooled engines, so
you wouldn't have the weight or complexity of a liquid cooling system.
They'd use parts that were common to the auto engines, so they'd have
the economy of scale thing going for them And it would help if they
did an opposed engine - you have to see over the cowl, after all, so
opposed or inverted engines have an advantage.
I know, let's get Porsche to get into the aircraft engine business!
_________________________________
Nice try.
Porsche did this very thing of course, calling it Porsche Flight Motors
out of Galesburg, Ill. As you well know.
Your attempt at sarcasm brings up a lot of facts:
1. A 911 Porsche engine in automotive configuration costs as much as a
Lycoming to overhaul. No liability, no certification, just the
willingness of Porsche people to pay stupid prices. Very much as simple
as that.
2. The cam chains have always been trouble on the 911 engine. They
denied it until blue in the face, but the PFM engines had gears.
3. Porsche no longer builds air cooled engines, neither does
Deutz...only H-D, Lyc and Teledyne Continental, purveyors of overpriced
junk to yuppies. As Dave Blanton said, all engines are liquid cooled.
Either by glycol around the valves or raw fuel through them.
4. Porsche would only sell their doubly overpriced-it was quite a bit
more than a Lycoming!-PFM to OEM buyers, of which only one existed,
namely Mooney.
5. You could see over the cowl a lot better with an engine with a
reduction drive putting the crank well below the propeller line and
still be able to have the induction on top of the engine where it
belongs. Additionally, the prop drive could be conveniently isolated
from the crank so that in the event of a gear up landing or noseover,
the engine would not need to be majored.
6. I never see Porsche engines in marine, drag, or circle track racing
and there are no ads for Porsche parts in the hot rod magazines they
sell at the 7-11. Porsches in racing are limited to high dollar road
racing, which Americans could generally care less about unless they are
loaded rich kids or actors like Haywood or Newman.
December 23rd 04, 02:03 AM
In rec.aviation.owning Richard Riley > wrote:
> On 22 Dec 2004 15:52:35 -0800, "Denny" > wrote:
> :If the Lycoming or Continental engine were really more reliable than
> :commodity general purpose engines, they'd be used in many other
> :applications. They are 1930s designs that if not protected by
> :certification would have been out of production for decades. General
> :purpose production engines have been installed in aircraft, usually by
> :people with a lack of resources in manufacturing and design, and yet
> :flown pretty well. If a company like Mercury Marine chose to get
> :involved in powerplants for experimental aircraft, they could put
> :Lycoming out of that market segment in a couple of years.
> How about a car company? I mean, if a company that produced high
> performance automotive engines got into the business, they'd own it,
> right? Especially if they had experience with air cooled engines, so
> you wouldn't have the weight or complexity of a liquid cooling system.
> They'd use parts that were common to the auto engines, so they'd have
> the economy of scale thing going for them And it would help if they
> did an opposed engine - you have to see over the cowl, after all, so
> opposed or inverted engines have an advantage.
> I know, let's get Porsche to get into the aircraft engine business!
Porsche was in the aircraft business; ever heard of the Porsche Mooney?
--
Jim Pennino
Remove -spam-sux to reply.
alexy
December 23rd 04, 12:41 PM
Gene Kearns > wrote:
>On Wed, 22 Dec 2004 16:56:38 -0500, alexy > wrote:
>
>
>>>Then by the same logic, that 8 cylinder engine in your automobile is
>>>"worth" $40,000+.
>>I don't see how that is the same logic. People are willing to pay
>
>How do you define, "willing." If you have a certificated aircraft with
>a certificated engine... your "will" has nothing to do with it.
Well, unless someone forced those planes on the owners against their
will, they in all likelihood wrote a check (maybe begrudgingly, but
definitely of their own free will) in exchange for that plane, the
cost of which included the engine.
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.
Gig Giacona
December 23rd 04, 05:57 PM
"Richard Riley" > wrote in message
...
>
> I know, let's get Porsche to get into the aircraft engine business!
Didn't Mooney try that?
Kyle Boatright
December 26th 04, 03:24 AM
"Denny" > wrote in message
oups.com...
> The manufacturers of certificated aircraft pay LyCon prices because the
> only alternative until very recently was an Allison or P&W turboprop at
> ten times the cost. I'm not sure any of the other supposedly
> certificated engines being talked of are 1) actually certificated in
> the U.S, and 2) actually shipping. The Zoche and DynaCam were thinly
> veiled efforts to pimp up some venture capital; neither had any real
> desire to produce engines.
>
> Homebuilders use these same engines because most homebuilders today
> just want to fly and are "building" as a dodge around type
> certification: most lack fabrication skills or any desire to
> experiment. Look at Richard Van Grunsven, who is making a lot of money
> on the RV kits. If people will pay those prices for sheet aluminum
> and assorted widgets why should he get his airplane certificated and
> tool up and manufacture them? His margins are as high as a certificated
> lightplane, he is making a lot of money with relatively little work.
Relatively little work? Hmm, I'd call designing, tooling, and fabricating,
and test flying 1 or 2 prototypes for each new aircraft significant. Add
production tooling costs, build manuals, etc, and the development costs for
each new type are probably surprising. Also, liability is probably a
significant cost for someone like Van's. Add Van's customer support and the
other benefits that come from their overhead (I'm sure they have 10x the
staff of any other kit manufacturer) and their prices are a pretty good
value.
> If the Lycoming or Continental engine were really more reliable than
> commodity general purpose engines, they'd be used in many other
> applications. They are 1930s designs that if not protected by
> certification would have been out of production for decades. General
> purpose production engines have been installed in aircraft, usually by
> people with a lack of resources in manufacturing and design, and yet
> flown pretty well. If a company like Mercury Marine chose to get
> involved in powerplants for experimental aircraft, they could put
> Lycoming out of that market segment in a couple of years.
And, being good capitalists, why didn't they do that? Because the market is
too small, the barriers to certification too high, and the liability is a
real monster. Apparently, they have decided that aviation isn't a
worthwhile market. If the aviation engine market was a panacea, you'd have
more than 2 real players. Right now, you don't. You have two, plus a
couple (Rotax and Jabiru) who are trying to make a go of it, then you can
add a few more which are perpetually "almost there", or "next year", or
whatever, but don't seem to ever get to market with product that earns and
keeps a place in the market.
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