MoGas Tips, Tricks, Concerns, How To

[Al Gilson]

We have a 1964 Cessna 172E with a Continental 0-300D. It has the
AutoGas STC, but we've never used anything but 100LL. We've had some
lead deposits and a stuck valve last spring.

With the rising cost of 100LL at our airport, I'm looking at starting to
use 87 Unleaded auto gas.

Is there a resource for tips on using MoGas? Filtering, checking for
alcohol, vapor lock problems, freshness, water, etc.

I've seen Jay's "Mightly Grape" on the web but that might be a little
overkill for us.

Right now our co-op is selling 100LL for $3.70 and MoGas is just under
$3. We'd save about $6 per hour on MoGas. Is it worth the risk and
hassle. I don't know how excited I can get about lifting a 5 gallon jub
up to fill a high-winger.

Just hungry for some info. Thanks in advance from the group.

Al

[Ron Wanttaja]

On Mon, 08 May 2006 18:33:22 -0700, Al Gilson > wrote:

> We have a 1964 Cessna 172E with a Continental 0-300D. It has the
> AutoGas STC, but we've never used anything but 100LL. We've had some
> lead deposits and a stuck valve last spring.
>
> With the rising cost of 100LL at our airport, I'm looking at starting to
> use 87 Unleaded auto gas.
>
> Is there a resource for tips on using MoGas? Filtering, checking for
> alcohol, vapor lock problems, freshness, water, etc.

For alcohol testing go to:

http://www.eaa26.org/apr06.pdf

and check page 5.

Ron Wanttaja

[[email protected]]

Al Gilson > wrote:
: We have a 1964 Cessna 172E with a Continental 0-300D. It has the
: AutoGas STC, but we've never used anything but 100LL. We've had some
: lead deposits and a stuck valve last spring.

That engine is allegedly *MUCH* happier on mogas than 100LL.

: Is there a resource for tips on using MoGas? Filtering, checking for
: alcohol, vapor lock problems, freshness, water, etc.

I've got a Cherokee I run mogas in. I debated on building a smaller version
of Jay's Grape... like a largish can on the hitch of my car, or maybe a small trailer.
I've ended up just using 5 gallon cans, with a pour-spout I built containing a
spin-on water-absorbing fuel filter. It really alleviates any contamination fears I
have from self-fueling from small cans.

I would probably be less excited about it if I had to lug each can up a ladder
to a high-wing. You might want to look for a 55-gallon drum with a hand (or
14v-powered) transfer pump to split the difference.

: Right now our co-op is selling 100LL for $3.70 and MoGas is just under
: $3. We'd save about $6 per hour on MoGas. Is it worth the risk and
: hassle. I don't know how excited I can get about lifting a 5 gallon jub
: up to fill a high-winger.

If the fuel is filtered and you test it for alcohol, the risk is pretty
minimal. Peterson has a vapor-pressure kit to test for that which we got when we
bought the STC. It's basically a syring with a vacuum gauge you screw on. Pull a
vacuum until the fuel sample "boils" and read the gauge. Even in the hottest of
summer days, the samples I've drawn are right on the bottom of the "OK" range. The
100LL I've pulled at the same time for comparison was only slightly better. I rarely
test that anymore.

: Just hungry for some info. Thanks in advance from the group.

I'd highly recommend it if you can do it. Between that an THOROUGHLY
understanding how to lean (or more importantly, the times when you cannot), you can
likely reduce the fuel bill and have a healthier engine.

-Cory

--

************************************************** ***********************
* Cory Papenfuss, Ph.D., PPSEL-IA *
* Electrical Engineering *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

[Jay Honeck]

> I've seen Jay's "Mightly Grape" on the web but that might be a little
> overkill for us.

Call it overkill -- but thus far I've saved over $6700 in fuel costs,
for the outlay of around $2200.

And counting...

:-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[M]

Also check out http://www.chouby.com/apps/autogas.html

For vapor lock prevention, the best thing to do is to open your cowling
right after shutdown to let the heat out, if you're going to take off
soon. It's a good thing to do anyway to extend the life of the hoses
under the cowling.

I found myself flying more frequently since I started using the autogas
STC. That's another benefit to the engine.

[.Blueskies.]

"Al Gilson" > wrote in message . ..
> We have a 1964 Cessna 172E with a Continental 0-300D. It has the AutoGas STC, but we've never used anything but
> 100LL. We've had some lead deposits and a stuck valve last spring.
>
> With the rising cost of 100LL at our airport, I'm looking at starting to use 87 Unleaded auto gas.
>
> Is there a resource for tips on using MoGas? Filtering, checking for alcohol, vapor lock problems, freshness, water,
> etc.
>
> I've seen Jay's "Mightly Grape" on the web but that might be a little overkill for us.
>
> Right now our co-op is selling 100LL for $3.70 and MoGas is just under $3. We'd save about $6 per hour on MoGas. Is
> it worth the risk and hassle. I don't know how excited I can get about lifting a 5 gallon jub up to fill a
> high-winger.
>
> Just hungry for some info. Thanks in advance from the group.
>
> Al

I do the 5 gallons up to the wing all the time on the 1960 172A. Good exercise and runs great. I put a old piece of
carpet under the fuel jug and then tip it over and in to the tank. Only spilt a drop or two in 100 of gallons. See:
http://www.eaa.org/education/fuel/index.html for all kinds of info. The engine runs fine winter and summer. I do put in
a little 100LL on occasion and when XC...

Dan D.

[Robert M. Gary]

Depends where you live. Many parts of the country put additives in
their mogas that is illegal according to the EAA's STC.

-Robert

[[email protected]]

: I do the 5 gallons up to the wing all the time on the 1960 172A. Good exercise and runs great. I put a old piece of
: carpet under the fuel jug and then tip it over and in to the tank. Only spilt a drop or two in 100 of gallons. See:
: http://www.eaa.org/education/fuel/index.html for all kinds of info. The engine runs fine winter and summer. I do put in
: a little 100LL on occasion and when XC...

If you do that, I'd be very careful to figure out a way to ground it. Plastic
cans on a piece of plastic fuzz carpet will insulate the can from the plane and let a
charge build up. Remember that flowing fuel *GENERATES* static electricity as it
pours. I've seen some impressive demonstrations of how much charge can be built up.
It was a 1" spark generated every 1-2 seconds just from flowing water.

That's what I consider to be another advantage of my filter-in-the-spout
setup. The 6-8" long-tall object screwed onto the spout is made of metal. Before I
get the spout near the fuel tank hole and as I start to tip it over to pour, I grab
the metal spout and touch the airframe elsewhere. I do that religiously each and
every time I pour anything into the tank. If there is any static, it'll dissipate
through me to the airframe and put both the spout and the airframe at the same
potential. I could rig up a wire to do the same, but as long as I never forget this
is just as good and more convenient.

-Cory


--

************************************************** ***********************
* Cory Papenfuss, Ph.D., PPSEL-IA *
* Electrical Engineering *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

[Montblack]

IIRC, years ago someone mention they bought an old Chevy Suburban, replaced
the (old) gas tank with a (new) aluminum-homemade-little-bit-larger one (50
gallons?) and pumped from that to his plane. Everything was new -
contamination worries low.

Hmm...IIRC is failing me this morning. Maybe it was a pickup truck with dual
tanks? Anyway, he built (new) aluminum gas tanks for his [beater] and no one
was the wiser at his airport. It was a covert operation Mogas situation
because of airport management - again, ....IIRC!


Montblack

[[email protected]]

: Hmm...IIRC is failing me this morning. Maybe it was a pickup truck with dual
: tanks? Anyway, he built (new) aluminum gas tanks for his [beater] and no one
: was the wiser at his airport. It was a covert operation Mogas situation
: because of airport management - again, ....IIRC!

Interesting. "Covert" shouldn't be necessary as it's illegal to prevent
self-fueling altogether (reasonable safety requirements are allowed). If it's tied
into the truck's fuel system however, it might not be considered bulk fuel
transportation though... and thus less regulations.

Interesting.

-Cory

--

************************************************** ***********************
* Cory Papenfuss, Ph.D., PPSEL-IA *
* Electrical Engineering *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

[nrp]

The major Mogas concern I have is that so few have endorsed the
concept, that it may not ever get to critical mass. The engine
manufacturers ignore it or don't support it, the AOPA never mentions
it, many FBOs simply state "our insurance won't cover it", the hodge
podge of state gasahol laws are eroding the practicality of it all, and
lastly we owners of low compression engines simply are not using it
anywhere near as much as we should.

Mogas is simply assumed by most "real pilots" and mechanics to be a
substitute fuel, inferior or harmful to engines, and something that is
only used by a small minority of old aircraft owners. For those and
probably still other reasons, mogas isn't widely available for cross
country use. The advantages of Mogas are only talked about in forums
such as these.

Mogas users have to get this situation changed. Some day 100LL is
going to disappear by an EPA mandate & then where will we be? I feel
the 100LL users are whistling in the dark as no substitutes seem to be
forthcoming to their leaded fuel.

[xyzzy]

nrp wrote:
> The major Mogas concern I have is that so few have endorsed the
> concept, that it may not ever get to critical mass. The engine
> manufacturers ignore it or don't support it, the AOPA never mentions
> it, many FBOs simply state "our insurance won't cover it", the hodge
> podge of state gasahol laws are eroding the practicality of it all, and
> lastly we owners of low compression engines simply are not using it
> anywhere near as much as we should.
>
> Mogas is simply assumed by most "real pilots" and mechanics to be a
> substitute fuel, inferior or harmful to engines, and something that is
> only used by a small minority of old aircraft owners. For those and
> probably still other reasons, mogas isn't widely available for cross
> country use. The advantages of Mogas are only talked about in forums
> such as these.
>
> Mogas users have to get this situation changed. Some day 100LL is
> going to disappear by an EPA mandate & then where will we be? I feel
> the 100LL users are whistling in the dark as no substitutes seem to be
> forthcoming to their leaded fuel.

Both Aviation Consumer and AOPA pilot have articles on this subject in
their current issues. They both conclude that 100LL is really not
going to be going away in the foreseeable future (the EPA has delegated
the issue the FAA and the FAA is not interested in getting rid of
100LL), and they also both describe research into alternatives that is
in fact going on now.

One statistic that interested me was that 70% of the GA fleet does not
have the high compression engines that need high octane/leaded fuel.
However, the 30% that does burns 70% of the gas.

[nrp]

It seemed as though the AOPA article ignored the proven success of
MoGas, but it did point out the very limited success of 100LL
alternatives. I wonder if there are any more high compression engines
running in test cells trying replacement fuels. It sounded like there
was only one.

[xyzzy]

nrp wrote:
> It seemed as though the AOPA article ignored the proven success of
> MoGas, but it did point out the very limited success of 100LL
> alternatives. I wonder if there are any more high compression engines
> running in test cells trying replacement fuels. It sounded like there
> was only one.

What is the proven success of Mogas? I mean, besides testimonials
from its users on this newsgroup, what proof is there of Mogas success,
and how would it be defined?

For example in their article on fuel, Aviation Consumer had a sidebar
on mogas saying it wasn't as good as advertised. They said several
shop owners told them that when they get engines or cylinders in for
work, they can immediately tell if the owner is running mogas by the
corroded camshafts and deposits on the valves and seats. These shop
owners claimed that the extra overhaul costs eliminate the mogas
savings, and attribute it to the "varying additives" used in mogas and
to the fact that most mogas sold doens't really meet the ASTM standards
dictated by the STC.

Personally I don't know, I have no experience with Mogas, all I have to
go on is what I read here and in other sources. It would be a pity if
this was correct, especially with rising 100LL prices.

[nrp]

I remember traveling in 1974 with a British engine engineering
consultant who was absolutely positive the US auto manufacturers were
going to be in for a rude surprise when unleaded fuels were foist upon
them by the EPA and the 1975 catalytic converter needs. He predicted
valves and seats would quickly fail creating a massive maintenance
problem.

It never happened. Hardened valve seats were used from the beginning,
and the reduction in engine contamination has given us longer service
intervals and incredibly long lived automotive engines today.

Where are the hardened seats for aircraft engines? Even something that
recognizes some fuels don't have TEL in them? I've lived with over 20
years of autofuel in my O-320-E2D (one of the first STCs from Petersen)
using low cruise powers, hoping to minimize valve seat recession. So
far I've been very successful.

The lack of a consistent airport distribution system to assure quality
for MoGas after 20 years is crazy. There must be other forces at work
that are not obvious to me.

[soxinbox]

I did not think the AOPA article ignored mogas. It is a solution for some
people, but not a solution for the market as a whole. You can't replace
100LL with mogas when 30% of the planes ( and 70% of the consumption ) can't
use it. You could offer it in parallel with the 100LL, but that would
require the small airports to pay for twice the deliveries, and have twice
the pumping equipment. The airports would also have to figure out how to
ensure the supply is not contaminated. Normal mogas delivery system is not
used to keeping things to a life critical quality. There would also have to
be changes in the tax code so that aviation taxes could be levied on the
mogas. The revenuers job would get harder because they would have to make
sure small airports didn't fill there tanks with mogas at the automobile tax
rate. It is only fair that the mogas aviators pay their share of the FAA and
ATC burden.

I am not saying the infrastructure could not be changed to use mogas, but it
would take the effort of the entire aviation community and the federal
government. There is a lot of inertia to overcome to save a few bucks.

I also agree with posters that claim that mogas can lead to early engine
wear. The fuels may be equivalent under normal circumstances, but if the
engine overheats, the low octane fuel will do a lot more damage than the
high octane fuel.

"nrp" > wrote in message
oups.com...
>I remember traveling in 1974 with a British engine engineering
> consultant who was absolutely positive the US auto manufacturers were
> going to be in for a rude surprise when unleaded fuels were foist upon
> them by the EPA and the 1975 catalytic converter needs. He predicted
> valves and seats would quickly fail creating a massive maintenance
> problem.
>
> It never happened. Hardened valve seats were used from the beginning,
> and the reduction in engine contamination has given us longer service
> intervals and incredibly long lived automotive engines today.
>
> Where are the hardened seats for aircraft engines? Even something that
> recognizes some fuels don't have TEL in them? I've lived with over 20
> years of autofuel in my O-320-E2D (one of the first STCs from Petersen)
> using low cruise powers, hoping to minimize valve seat recession. So
> far I've been very successful.
>
> The lack of a consistent airport distribution system to assure quality
> for MoGas after 20 years is crazy. There must be other forces at work
> that are not obvious to me.
>

[Jay Honeck]

> I also agree with posters that claim that mogas can lead to early engine
> wear. The fuels may be equivalent under normal circumstances, but if the
> engine overheats, the low octane fuel will do a lot more damage than the
> high octane fuel.

That is simply not true. Perpetuating a myth like that in this forum
is not productive.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Jay Honeck]

> For example in their article on fuel, Aviation Consumer had a sidebar
> on mogas saying it wasn't as good as advertised. They said several
> shop owners told them that when they get engines or cylinders in for
> work, they can immediately tell if the owner is running mogas by the
> corroded camshafts and deposits on the valves and seats. These shop
> owners claimed that the extra overhaul costs eliminate the mogas
> savings, and attribute it to the "varying additives" used in mogas and
> to the fact that most mogas sold doens't really meet the ASTM standards
> dictated by the STC.

I read that article, and it is the closest thing to total bull**** I've
ever read on the subject. I can line up several shop owners who will
absolutely contradict the statements of those supposed "shop owners".


Nearly every INDEPENDENT shop owner I know (and that distinction seems
to be critical here) will testify that engines that have ran on
unleaded fuels are MUCH cleaner inside. They will tell you that they
can tell instantly upon teardown whether someone has been burning 100
LL in an engine that was designed to run on 80 octane avgas, simply by
the amount of crud inside.

100 LL has FOUR TIMES the amount of lead that my engine was designed to
run with. As a result, spark plugs foul with lead far easier, making
it necessary to aggressively lean the engine. Which, of course, in
turn leads to much higher exhaust gas temperatures, and unnecessary
wear and tear on the engine.

The ONLY time I've ever had engine trouble with Atlas' O-540 was on a
road trip where I was forced to run exclusively 100LL for days on end.
I fouled a cylinder so badly that BOTH spark plugs ceased firing,
requiring a quick return to the airport landing, (Not QUITE an
emergency, but close...)

I would run 87 octane unleaded car gas in my engine if it cost MORE
than 100LL. My engine simply runs better and cleaner on it, and I will
not run 100 LL unless I am forced to use it.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[jim]

Have to agree with you Jay. I've had both my engines apart before and
after running Mogas for some time and both were much cleaner after
Mogas. Simply far less combustion chamber deposits, cleaner valves with
no measurable valve seat change. I notice no difference in the way my
0-360 Lyc runs but a big improvement in the way my 0-300D Cont runs.
One can forget about it until going cross country where no Mogas is
available and it starts running finaky again.
I figure if I'm too weak to lift a 5 gallon container of gas up onto
the wing then I'm too weak to fly and better get another pass time (or
let my wife do it. after all its her plane).
Jim

Jay Honeck wrote:
> > For example in their article on fuel, Aviation Consumer had a sidebar
> > on mogas saying it wasn't as good as advertised. They said several
> > shop owners told them that when they get engines or cylinders in for
> > work, they can immediately tell if the owner is running mogas by the
> > corroded camshafts and deposits on the valves and seats. These shop
> > owners claimed that the extra overhaul costs eliminate the mogas
> > savings, and attribute it to the "varying additives" used in mogas and
> > to the fact that most mogas sold doens't really meet the ASTM standards
> > dictated by the STC.
>
> I read that article, and it is the closest thing to total bull**** I've
> ever read on the subject. I can line up several shop owners who will
> absolutely contradict the statements of those supposed "shop owners".
>
>
> Nearly every INDEPENDENT shop owner I know (and that distinction seems
> to be critical here) will testify that engines that have ran on
> unleaded fuels are MUCH cleaner inside. They will tell you that they
> can tell instantly upon teardown whether someone has been burning 100
> LL in an engine that was designed to run on 80 octane avgas, simply by
> the amount of crud inside.
>
> 100 LL has FOUR TIMES the amount of lead that my engine was designed to
> run with. As a result, spark plugs foul with lead far easier, making
> it necessary to aggressively lean the engine. Which, of course, in
> turn leads to much higher exhaust gas temperatures, and unnecessary
> wear and tear on the engine.
>
> The ONLY time I've ever had engine trouble with Atlas' O-540 was on a
> road trip where I was forced to run exclusively 100LL for days on end.
> I fouled a cylinder so badly that BOTH spark plugs ceased firing,
> requiring a quick return to the airport landing, (Not QUITE an
> emergency, but close...)
>
> I would run 87 octane unleaded car gas in my engine if it cost MORE
> than 100LL. My engine simply runs better and cleaner on it, and I will
> not run 100 LL unless I am forced to use it.
> --
> Jay Honeck
> Iowa City, IA
> Pathfinder N56993
> www.AlexisParkInn.com
> "Your Aviation Destination"

[RK Henry]

On 10 May 2006 13:24:27 -0700, "xyzzy" > wrote:

>For example in their article on fuel, Aviation Consumer had a sidebar
>on mogas saying it wasn't as good as advertised. They said several
>shop owners told them that when they get engines or cylinders in for
>work, they can immediately tell if the owner is running mogas by the
>corroded camshafts and deposits on the valves and seats. These shop
>owners claimed that the extra overhaul costs eliminate the mogas
>savings, and attribute it to the "varying additives" used in mogas and
>to the fact that most mogas sold doens't really meet the ASTM standards
>dictated by the STC.

Junk science from the aircraft maintenance industry. Since auto gas
STCs generally prohibit commercial operations, you can expect that if
an airplane is being flown on auto gas that it's probably going to be
on weekends by pilots who have to work for a living the rest of the
week. That's the kind of operation that has already been documented to
cause corrosion on camshafts, regardless of fuel. And as for deposits
on valves, how could auto gas deposits be any worse than the deposits
caused by 100LL? Lead deposits have been documented to cause valve
burning, valve sticking, ring sticking, spark plug fouling, and
in-flight engine failure. That's a major reason why we're running
mogas. A claim like that might make sense if they noted a lack of
deposits as being the indicator of auto gas operation.

I'd be more impressed if these people would publish objective,
scientifically controlled studies instead of anecdotal observations.
As it happens, the only people who have done studies have found no
problems with auto gas.

It is noteworthy that the FAA has given its blessing to 82UL avgas,
which, being based on auto gas, contains no lead. It's FAA approved,
so it must be ok, right? Of course I doubt that anyone now living will
ever see it at our local airports.

And then there's NASCAR. After years of noise from environmentalists,
NASCAR has announced that they've developed and are beginning to use
an unleaded alternative to the leaded racing gasoline they'd been
using, which was essentially the same stuff we fly with. Once the
environmentalists get through with NASCAR, don't you wonder how long
it'll take for them to draw a bead on us? They may ask that EPA start
testing air quality around airports just like they asked the EPA to
test air quality at NASCAR races. EPA says they're not interested in
doing anything about avgas, but that could change with a single
election or a single court decision.

RK Henry

[nrp]

If I have not had too long a taxi, I can wipe the INSIDE of the exhaust
stack on my O-320 with a white handkerchief and get very little
smudging. I've never experienced a rough mag (or sticking valve) in
its 1700 hrs. Spark plugs are cleaned as an annual insp formality.

A solution that might be explored by non-turboed 100LL users is to use
a combination of FADEC and reduce the compression ratio as necessary to
use auto premium, and reduce the gross weight of the aircraft if
necessary to maintain performance.

I have no answer for turboed aircraft except to note that they are used
primarily at higher altitudes where the compression ratio is not a
limiting factor. Intercoolers would be have to be used universally.

Then we would be down to one environmentally tolerable fuel for piston
engines.

[Dave Stadt]

"xyzzy" > wrote in message
oups.com...
>
> nrp wrote:
>> The major Mogas concern I have is that so few have endorsed the
>> concept, that it may not ever get to critical mass. The engine
>> manufacturers ignore it or don't support it, the AOPA never mentions
>> it, many FBOs simply state "our insurance won't cover it", the hodge
>> podge of state gasahol laws are eroding the practicality of it all, and
>> lastly we owners of low compression engines simply are not using it
>> anywhere near as much as we should.
>>
>> Mogas is simply assumed by most "real pilots" and mechanics to be a
>> substitute fuel, inferior or harmful to engines, and something that is
>> only used by a small minority of old aircraft owners. For those and
>> probably still other reasons, mogas isn't widely available for cross
>> country use. The advantages of Mogas are only talked about in forums
>> such as these.
>>
>> Mogas users have to get this situation changed. Some day 100LL is
>> going to disappear by an EPA mandate & then where will we be? I feel
>> the 100LL users are whistling in the dark as no substitutes seem to be
>> forthcoming to their leaded fuel.
>
> Both Aviation Consumer and AOPA pilot have articles on this subject in
> their current issues. They both conclude that 100LL is really not
> going to be going away in the foreseeable future (the EPA has delegated
> the issue the FAA and the FAA is not interested in getting rid of
> 100LL), and they also both describe research into alternatives that is
> in fact going on now.

Somehow I don't believe the oil companies are going to base their business
on what the FAA and AOPA think is going to happen.

[Matt Barrow]

"nrp" > wrote in message
oups.com...
> It seemed as though the AOPA article ignored the proven success of
> MoGas, but it did point out the very limited success of 100LL
> alternatives. I wonder if there are any more high compression engines
> running in test cells trying replacement fuels. It sounded like there
> was only one.

GAMI has been running a Lycoming GTSIO-540 on a test stand using rot gut gas
using it's PRISM system without a burp, and hoping for an STC when they can
work out vibration tests.

http://www.gami.com/prism.html

[Matt Barrow]

"Jay Honeck" > wrote in message
oups.com...
>> For example in their article on fuel, Aviation Consumer had a sidebar
>> on mogas saying it wasn't as good as advertised. They said several
>> shop owners told them that when they get engines or cylinders in for
>> work, they can immediately tell if the owner is running mogas by the
>> corroded camshafts and deposits on the valves and seats. These shop
>> owners claimed that the extra overhaul costs eliminate the mogas
>> savings, and attribute it to the "varying additives" used in mogas and
>> to the fact that most mogas sold doens't really meet the ASTM standards
>> dictated by the STC.
>
> I read that article, and it is the closest thing to total bull**** I've
> ever read on the subject. I can line up several shop owners who will
> absolutely contradict the statements of those supposed "shop owners".
>
>
> 100 LL has FOUR TIMES the amount of lead that my engine was designed to
> run with. As a result, spark plugs foul with lead far easier, making
> it necessary to aggressively lean the engine. Which, of course, in
> turn leads to much higher exhaust gas temperatures, and unnecessary
> wear and tear on the engine.

Now that's bull****. Aggressive leaning is COOLER when done properly (i.e.,
using the proper temp range when LOP. It also produces lower internal
cylinder pressures, more through combustion, lower CHT temps.

[Newps]

>>
>>
>>100 LL has FOUR TIMES the amount of lead that my engine was designed to
>>run with. As a result, spark plugs foul with lead far easier, making
>>it necessary to aggressively lean the engine. Which, of course, in
>>turn leads to much higher exhaust gas temperatures, and unnecessary
>>wear and tear on the engine.


Geez Jay, better get yourself educated on leaning. Leaning properly on
the ground means way, way lean of peak which by definition is downright
cold EGT's although on the ground at low power there's no such thing as
high EGT. You need to familiarize yourself with the red box when it
comes to leaning. Done properly the EGT's are as cool or cooler than
rich of peak and the CHT's are significantly cooler. An example is that
about the worst place to run your engine while at 75% would be 60-80
degrees rich of peak.

[David Lesher]

"nrp" > writes:


>Mogas users have to get this situation changed. Some day 100LL is
>going to disappear by an EPA mandate & then where will we be? I feel
>the 100LL users are whistling in the dark as no substitutes seem to be
>forthcoming to their leaded fuel.


I have to agree; the refiners want to dump any TEL product; the EPA wants
them to do so; the whole national market is the size of a decimal point
to the distribution side.....


--
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

[Jay Honeck]

> Geez Jay, better get yourself educated on leaning. Leaning properly on
> the ground means way, way lean of peak which by definition is downright
> cold EGT's although on the ground at low power there's no such thing as
> high EGT.

Welcome to 1952, where you have to move levers on the panel in order to
make your plane run properly while on the ground. And you say MOGAS is
bad? Strange how I have to do none of that, when I run with mogas.
The engine just purrs like a kitten, without any input from me at all.

Of course it's *possible* to run avgas in my engine with minimal
fouling of the plugs. All I've got to do is pull that red lever back
until the engine coughs and sputters, and then push it in a tiny bit
more. But do you really think that it's better to run an engine with
stuff that REQUIRES such bizarre (outside of the aviation world) engine
management?

How in the world did pilots ever come to accept a fuel that they know
won't run in their engines without aggressive leaning? Can you
imagine selling a fuel like this to car owners?

"Well, sir, this fuel is usable in your car only at speeds of 45 mph
and above. Below that speed, you'll have to pull this little lever out
-- but only until the engine sputters a bit. Then push it back in a
bit, and you SHOULD be okay..."

It would be laughable, if it weren't considered "the norm" by so many
pilots...
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Frank Stutzman]

Jay Honeck > wrote:
>> Now that's bull****. Aggressive leaning is COOLER when done properly (i.e.,
>> using the proper temp range when LOP. It also produces lower internal
>> cylinder pressures, more through combustion, lower CHT temps.
>
> Not in a carbureted engine. The fuel flows are simply not matched well
> enough between cylinders to run lean of peak without risking damage.
>
> Now, in a fuel-injected engine (especially with GAMI), that's a whole
> different world. But in the low compression carbureted world, you run
> rich of peak, or you risk destroying your engine.

Again, untrue, Jay.

The Continental E-225 (with a PS5-C carburator) in my Bonanzan runs just fine LOP.
I can't quite get as far LOP as my fuel injected bretheren. About 25-30 degrees
LOP seems to be about as far as it goes. Would you like to see the downloads
from my JPI?

Walter Atkinson (sp?) of GAMI has told me he routinely operated a carbed
Cessna 182 (O-470) LOP. In order for it to be smooth he had to play with the
throttle and carb heat some, though.

Now, if you had said that you can't run a carbed Lycoming engine LOP I might
have given you a bit of slack. I think it still can be done, but I think
its much more difficult.

--
Frank Stutzman
Bonanza N494B "Hula Girl"
Hood River, OR

[[email protected]]

Jay Honeck > wrote:
: Now, in a fuel-injected engine (especially with GAMI), that's a whole
: different world. But in the low compression carbureted world, you run
: rich of peak, or you risk destroying your engine.

Sorry Jay, but it's not necessarily so cut-n-dried. Yes, fuel distribution is
rather poor in your flat six. Not quite as bad in my flat four, but I still have
uneven fuel distribution. The real issue is knowing *FOR SURE* what power setting
you are at and never exceeding the POH amount. Lycoming says essentially *ANY*
mixture setting is fine if you stay below 75% and 450 degrees CHT. I personally don't
like to run it that close and use the more conservative 65% and 375 degrees CHT. At
those power settings and temperatures, you cannot damage your engine with the red
knob. You can lean it until it wheezes if the CHT stays cool enough.

Now, whether or not it runs smoothly there is an entirely different matter....
one of vibration acceptability. Having some above peak and some below peak EGT is
fine if you keep the power and temps low enough.

-Cory

--

************************************************** ***********************
* Cory Papenfuss, Ph.D., PPSEL-IA *
* Electrical Engineering *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

[Matt Barrow]

"Jay Honeck" > wrote in message
oups.com...
>> Geez Jay, better get yourself educated on leaning. Leaning properly on
>> the ground means way, way lean of peak which by definition is downright
>> cold EGT's although on the ground at low power there's no such thing as
>> high EGT.
>
> Welcome to 1952, where you have to move levers on the panel in order to
> make your plane run properly while on the ground. And you say MOGAS is
> bad? Strange how I have to do none of that, when I run with mogas.
> The engine just purrs like a kitten, without any input from me at all.

Nice change of subject when caught with your pants down.

[Matt Barrow]

"Jay Honeck" > wrote in message
oups.com...
>> Now that's bull****. Aggressive leaning is COOLER when done properly
>> (i.e.,
>> using the proper temp range when LOP. It also produces lower internal
>> cylinder pressures, more through combustion, lower CHT temps.
>
> Not in a carbureted engine.

Yes, in a carburated engine.

> The fuel flows are simply not matched well
> enough between cylinders to run lean of peak without risking damage.

That's a seperate issue, but even that's not completely right. The issue
there is the ****ty fuel distribution in horizontally opposed engines. That
includes carb engines and FI. The issue IS the sloppy (horrendously) design
and workmanship that the two big boys have been getting us schmucks to buy
into for the past couple generations.

Go and read about the P&W radials and how they ran them during the
carburation days, then put the book on display in your hotels library.

>
> Now, in a fuel-injected engine (especially with GAMI), that's a whole
> different world. But in the low compression carbureted world, you run
> rich of peak, or you risk destroying your engine.

You run rich of peak in the wrong range and you still mess up your engine,
high compression or low, Mogas or Avgas, carbureted or FI'ed.

[Matt Barrow]

"nrp" > wrote in message
ups.com...
> Dick Collins in Flying mag had a new '75 Skyhawk that he tried to run
> on 100LL using aggressive leaning techniques. I recall he got to 800
> hours TT before writing a bitter editorial (who would do THAT nowdays?)
> about his engine's bad case of lead poisoning, and ended with " a four
> cylinder engine running on three cylinders gives a message that's hard
> to ignore".

What engine does the 75 Skyhawk carry?

Collins also wrote an article about a year ago (June '05 ?) after putting
GAMI's in his P210 castigating LOP. GAMI and Mac McClellan both returned the
broadside as it was obvious he didn't bother to learn the techniques. The
manager at GAMI, Tim Roehl, stated in an email, "He has never asked us for
assistance in getting it right, or doing it right. We have invited him to
come visit us and fly with us, to no avail. I guess he must know
everything. Disappointing to mislead so many people in the perseverance of
such "old wives tales."

GAMI's Jean-Paul Townsend stated in an email, " I would personally pay the
$995 for him to go to the Advanced Pilot Seminar. He has been offered a
gratis seat before, but he won't take it."

Say le vie, I guess.


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

[M]

People seem to ignore the fact that lead dibromide, the byproduct of
burning 100LL, is acidic highly corrosive when mixed with water, which
is also plenty as a result of combustion.

Lead dibromide is formed when Tetra-ethyl lead react swith lead
scavenging agent ethylene dibromide during the combustion. The lead
scavenging agent is a necessary evil to get rid of the metalic lead
after TEL does it job of retarding the combustion. Without it the
metalic lead will quickly accumulate in the engine as slush.

Other than its high octane value (which isn't needed in 1:7 compression
engines), 100LL isn't such a good fuel to begin with.

[nrp]

Collins 172 engine was same as mine. Lyc O-320E2D low compression.
Only mine has been fed a minimum lead diet to get 1700 hrs TT & 30
years since new (i. e. no OH!).

Interesting RC attitudes on the GAMI observations. I think he was very
aggressive in leaning his 172 to the point of roughness - and he got
plenty of that thru the years he had it. At the time though his 172
problems sure scared hell out of us & our (then) new bird. His is
history. We still have ours.

[Newps]

Jay Honeck wrote:
>>Geez Jay, better get yourself educated on leaning. Leaning properly on
>>the ground means way, way lean of peak which by definition is downright
>>cold EGT's although on the ground at low power there's no such thing as
>>high EGT.
>
>
> Welcome to 1952, where you have to move levers on the panel in order to
> make your plane run properly while on the ground. And you say MOGAS is
> bad?

I never said that. I used it for 7 years in my 182, wish I could still
use it. You seem to have a real bummer of an engine. I don't really
lean on the ground with my 520 and don't have any problems.


Strange how I have to do none of that, when I run with mogas.
> The engine just purrs like a kitten, without any input from me at all.

Ditto here.

[Montblack]

("M" wrote)
> Lead dibromide is formed when Tetra-ethyl lead react swith lead scavenging
> agent ethylene dibromide during the combustion. The lead scavenging agent
> is a necessary evil to get rid of the metalic lead after TEL does it job
> of retarding the combustion. Without it the metalic lead will quickly
> accumulate in the engine as slush.


Do you know how many lbs. of actual lead are in ...100 gallons of 100LL?

Curious ....unfortunately, so are the Green Meanies.


Montblack
<http://www.sensesofcinema.com/contents/cteq/03/26/yellow_submarine.html>
Blue Meanie

[Jim Logajan]

"Montblack" > wrote:
> Do you know how many lbs. of actual lead are in ...100 gallons of
> 100LL?

From http://en.wikipedia.org/wiki/Avgas :
"Avgas 100LL contains a maximum of 2 grams of lead per US gallon"

[M]

So you point is that lead scavenging agent isn't needed because there's
not that much lead in the 100LL?

[karl gruber]

"M" > wrote in message
oups.com...
> People seem to ignore the fact that lead dibromide, the byproduct of
> burning 100LL, is acidic highly corrosive when mixed with water, which
> is also plenty as a result of combustion.
>
> Lead dibromide is formed when Tetra-ethyl lead react swith lead
> scavenging agent ethylene dibromide during the combustion. The lead
> scavenging agent is a necessary evil to get rid of the metalic lead
> after TEL does it job of retarding the combustion. Without it the
> metalic lead will quickly accumulate in the engine as slush.
>
> Other than its high octane value (which isn't needed in 1:7 compression
> engines), 100LL isn't such a good fuel to begin with.
>

Baloney. 100LL is the best fuel made and can't be duplicated Your problems
sound like "The sky is falling"

Karl
ATP CFI ETC
"Curator N185KG

[[email protected]]

On Thu, 11 May 2006 10:08:01 -0700, "Matt Barrow"
> wrote:

>
>"Jay Honeck" > wrote in message
oups.com...
>>> Geez Jay, better get yourself educated on leaning. Leaning properly on
>>> the ground means way, way lean of peak which by definition is downright
>>> cold EGT's although on the ground at low power there's no such thing as
>>> high EGT.
>>
>> Welcome to 1952, where you have to move levers on the panel in order to
>> make your plane run properly while on the ground. And you say MOGAS is
>> bad? Strange how I have to do none of that, when I run with mogas.
>> The engine just purrs like a kitten, without any input from me at all.
>
>Nice change of subject when caught with your pants down.
>

curious who was right there to jump on, also.

TC

[Montblack]

("M" wrote)
> So you point is that lead scavenging agent isn't needed because there's
> not that much lead in the 100LL?


My curiosity was: What quantity (by weight) of lead is in 100 gallons of
100LL?

I picked 100 gallons because I didn't want some small fraction. As it turns
out, 2 grams/gallon is not a small fraction.

I used the term "actual lead" because I wanted to know the amount of lead
left behind if "everything" else were to be distilled away.

My side point was: Lead = "ATTACK!" to the Greens ...1 gram, 2 grams, 15
grams, 0.14 grams, doesn't matter to them - it's LEAD!!!

[Thanks to Jim L]
From http://en.wikipedia.org/wiki/Avgas :
"Avgas 100LL contains a maximum of 2 grams of lead per US gallon"

1,000 grams (kilo) = 2.2 lbs
500 gallons of 100LL = 2.2 lbs of lead.

Now the world make sense to me.


Montblack
"Hello, Thielert..."

http://www.dieselair.com/
Diesel updates for airplanes

[M]

I see. My point on the other hand has nothing to do with the lack of
greeness of 100LL. My point is that the bromine in the lead scavenging
agent is corrosive to the engine after the combustian event. We live
with it because the high compression engine needs it to get rid of the
lead. But for 1:7 compression engines this corrosive compound is an
entirely unnecessary evil because the engine doesn't need the extra
octane from TEL. By getting rid of TEL we get rid of bromine in the
engine (lead bromide reacts with water to form hydrobromide acid). Too
bad mogas is the only unleaded fuel we can get for our LC engines at
this point.

[Montblack]

("M" wrote)
<Too bad mogas is the only unleaded fuel we can get for our LC engines at
this point.


What would your unleaded fuel of choice be?

How would it be different than MoGas?

Um, hydrogen? propane? 100% ethanol?


Montblack

[M]

An unleaded aviation fuel with the same quality control and tracking as
100LL would be ideal. Unfortunatley that's not going to happen anytime
soon. For the time being I'll just keep doing my own alcohol test and
filling up with mogas.

[soxinbox]

1> The octane measurement is an attempt to quantify a fuels propensity for
detonation or pre combustion. Higher octane means less propensity.
2> Precombustion and detonation are usually caused by, among other things,
engine overheating, and hot spots.
3> Precombustion and detonation can lead to further increases in CHT.
4> Precombustion and detonation can damage an engine.
5> High CHTs can damage an engine.

Let me know which of the above statements you disagree with, and I will find
a reference for it.
I stand by my statement that an overheated engine will be more damaged if it
is running lower octane fuel.

"Jay Honeck" > wrote in message
oups.com...
>> I also agree with posters that claim that mogas can lead to early engine
>> wear. The fuels may be equivalent under normal circumstances, but if the
>> engine overheats, the low octane fuel will do a lot more damage than the
>> high octane fuel.
>
> That is simply not true. Perpetuating a myth like that in this forum
> is not productive.
> --
> Jay Honeck
> Iowa City, IA
> Pathfinder N56993
> www.AlexisParkInn.com
> "Your Aviation Destination"
>

[Bela P. Havasreti]

Perhaps a more useful comparison would be how much
lead is/was in 80/87 vs 100LL?

Those of use with older, low compression engines that were designed
to run on 80/87 may be introducing 4 times the amount of lead into our
combustion chambers by running 100LL than the original designers had
intended for.

80/87 has a maximum of 0.5 grams of lead per US gallon while 100LL has
a maximum of 2.0 grams of lead per US gallon. Unleaded Mogas is...
well... Unleaded!

In reading about this somewhere (AvWeb? EAA?) I recall words to the
effect that the refineries can get up to about 97 octane without any
lead, and they only add as much in to get to (or slightly exceed) the
100 octane rating.

I have the EAA Mogas STC for my C-170B, and the paperwork states if
you mix a certain amount of 100LL with unleaded Mogas (25% to 75%),
you get approximately the same amount of lead as you would have had
with a tank-full of 80/87.

For what it's worth, my O-300 absolutely *hates* straight 100LL (way
too much lead). Aggressive leaning, both on the ground and in the
air, can extend the time between fouled pugs and stuck valves, but
both are virtually inevitable without a lead scavenging agent (like
TCP) or using Marvel Mystery Oil, etc.

I burn Mogas on local flights and when/where I can get it on cross
country flights. When I have to fuel up with straight 100LL, I add
TCP.

Not only is the Mogas cheaper, I no longer have to worry about
fouled plugs and stuck valves! (aka a "no-brainer"). 8^)

Bela P. Havasreti

[Jay Honeck]

> Let me know which of the above statements you disagree with, and I will find
> a reference for it.
> I stand by my statement that an overheated engine will be more damaged if it
> is running lower octane fuel.

None of your statements are incorrect, they are merely irrelevant.

Low-compression aircraft engines were designed to run on 80 octane
fuel. Running fuel of higher octane is not going to hurt anything --
but it won't help, either.

87 octane auto gas is perfect for our low compression engines, and
certainly won't hurt them. Using "premium" (or, for that matter, 100
LL) is neither necessary nor recommended.

(Note: SOME mogas STCs do require using a higher octane car gas, but
those are the exception, not the rule.)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Jay Honeck]

> I wonder about the effect of LOP on muffler life. I used just the
> low-power-operate-at-peak philosophy and my 172 went thru the muffler
> internal flame tubes every 450 hrs, like it could read the hour meter.

As posted before, the head honcho at Dawley Aviation (the exhaust
system folks in Burlington, WI) told me personally that running lean of
peak has been the best thing that EVER happened to their business.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Matt Barrow]

"nrp" > wrote in message
ups.com...
> Collins 172 engine was same as mine. Lyc O-320E2D low compression.
> Only mine has been fed a minimum lead diet to get 1700 hrs TT & 30
> years since new (i. e. no OH!).

And as stated elsewhere, the LOP procedure doesn't work with the crappy
fuel/air distribution systems in HO engines with carburation or FI.

> Interesting RC attitudes on the GAMI observations. I think he was very
> aggressive in leaning his 172 to the point of roughness - and he got
> plenty of that thru the years he had it. At the time though his 172
> problems sure scared hell out of us & our (then) new bird. His is
> history. We still have ours.

I'm coming up on 1500 hours in mine which has been run 60LOP for five years.
That has been all 100LL. The last annual/maint showed virtually pristine
cylinders and plugs.

If someone has the right fuel availability/engine combination, then hell
yes, use Mogas. 100LL here is $4.15 a gallon and that's pricy, so using
Mogas would be "more better", but not with my engine.

The issue with Collins and the article he wrote was the situation with his
P210, not his Skyhawk. Like so many others, he jumped in without learning
the method. It was shear blockheadedness.

[Matt Barrow]

> wrote in message
...
> On Thu, 11 May 2006 10:08:01 -0700, "Matt Barrow"
> > wrote:
>
>>
>>"Jay Honeck" > wrote in message
oups.com...
>>>> Geez Jay, better get yourself educated on leaning. Leaning properly on
>>>> the ground means way, way lean of peak which by definition is downright
>>>> cold EGT's although on the ground at low power there's no such thing as
>>>> high EGT.
>>>
>>> Welcome to 1952, where you have to move levers on the panel in order to
>>> make your plane run properly while on the ground. And you say MOGAS is
>>> bad? Strange how I have to do none of that, when I run with mogas.
>>> The engine just purrs like a kitten, without any input from me at all.
>>
>>Nice change of subject when caught with your pants down.
>>
>
> curious who was right there to jump on, also.
>
Umm...the original poster?

[Jay Honeck]

> > Other than its high octane value (which isn't needed in 1:7 compression
> > engines), 100LL isn't such a good fuel to begin with.
>
> Baloney. 100LL is the best fuel made and can't be duplicated Your problems
> sound like "The sky is falling"

That's a good one!

Er, um...that *was* meant to be funny...right?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Matt Barrow]

"Bela P. Havasreti" > wrote in message
...
> Perhaps a more useful comparison would be how much
> lead is/was in 80/87 vs 100LL?
>
> Those of use with older, low compression engines that were designed
> to run on 80/87 may be introducing 4 times the amount of lead into our
> combustion chambers by running 100LL than the original designers had
> intended for.
>
> 80/87 has a maximum of 0.5 grams of lead per US gallon while 100LL has
> a maximum of 2.0 grams of lead per US gallon. Unleaded Mogas is...
> well... Unleaded!
>
> In reading about this somewhere (AvWeb? EAA?) I recall words to the
> effect that the refineries can get up to about 97 octane without any
> lead, and they only add as much in to get to (or slightly exceed) the
> 100 octane rating.

This one: http://www.avweb.com/news/columns/182149-1.html

[Matt Barrow]

"Jay Honeck" > wrote in message
oups.com...
>> I wonder about the effect of LOP on muffler life. I used just the
>> low-power-operate-at-peak philosophy and my 172 went thru the muffler
>> internal flame tubes every 450 hrs, like it could read the hour meter.
>
> As posted before, the head honcho at Dawley Aviation (the exhaust
> system folks in Burlington, WI) told me personally that running lean of
> peak has been the best thing that EVER happened to their business.

And has been pointed out in this group previously, he's full of ****.

[Bob Fry]

>>>>> "MB" == Montblack > writes:

MB> What would your unleaded fuel of choice be?

Good old 80/87. But that's not coming back.

[David Lesher]

"Montblack" > writes:

><Too bad mogas is the only unleaded fuel we can get for our LC engines at
>this point.

>What would your unleaded fuel of choice be?


#2 Diesel....

--
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

[soxinbox]

If you run your car engine on 80 octane mogas, it will usually run fine. If
your car overheats, it will start to knock. If you have 100 octane gas it
will start to knock at a higher CHT than if you ran at 80 octane. This is
not usually a problem in a car that has a radiator and thermostat to
regulate the temperature.

In an airplane the same is true. Run normally both octanes are fine. In an
airplane with a manually adjusted mixture being the only temperature control
( ignoring cowl flaps) it is much easier to overheat an engine. If your CHTs
get to high, it will start to knock. With a higher octane gas it will start
to knock at higher CHTs. Therefore, if you overheat your engine, the lower
octane gas will cause more damage than the higher octane gas. Hopefully I
have drawn a clear enough line between the statements that you said were all
true and the conclusion you said was not.

"Jay Honeck" > wrote in message
oups.com...
>> Let me know which of the above statements you disagree with, and I will
>> find
>> a reference for it.
>> I stand by my statement that an overheated engine will be more damaged if
>> it
>> is running lower octane fuel.
>
> None of your statements are incorrect, they are merely irrelevant.
>
> Low-compression aircraft engines were designed to run on 80 octane
> fuel. Running fuel of higher octane is not going to hurt anything --
> but it won't help, either.
>
> 87 octane auto gas is perfect for our low compression engines, and
> certainly won't hurt them. Using "premium" (or, for that matter, 100
> LL) is neither necessary nor recommended.
>
> (Note: SOME mogas STCs do require using a higher octane car gas, but
> those are the exception, not the rule.)
> --
> Jay Honeck
> Iowa City, IA
> Pathfinder N56993
> www.AlexisParkInn.com
> "Your Aviation Destination"
>

[Matt Barrow]

"soxinbox" > wrote in message
...
> If you run your car engine on 80 octane mogas, it will usually run fine.
> If your car overheats, it will start to knock. If you have 100 octane gas
> it will start to knock at a higher CHT than if you ran at 80 octane. This
> is not usually a problem in a car that has a radiator and thermostat to
> regulate the temperature.

I can't remember seeing anything less than 85 octane car gas since, oh,
maybe the 60's?

[Jay Masino]

Jay Honeck > wrote:
> 87 octane auto gas is perfect for our low compression engines, and
> certainly won't hurt them. Using "premium" (or, for that matter, 100
> LL) is neither necessary nor recommended.
>
> (Note: SOME mogas STCs do require using a higher octane car gas, but
> those are the exception, not the rule.)

Don't forget, MANY planes are not considered low compression, even though
they're not exactly "high performance". For example, all the 160 hp versions
of the O-320 found in many Cherokees, Warriors, C-172s, etc, as well as the
normally aspirated 180 hp O-360 found in Cherokee 180s, REQUIRE higher octane
than 87 octane car gas. I believe, for most of them, they could get by with
less than 100, but would certainly need super unleaded as a minimum.

--- Jay


--

Jay Masino "Home is where the critters are"
http://www.JayMasino.com
http://www.OceanCityAirport.com
http://www.oc-Adolfos.com

[[email protected]]

: than 87 octane car gas. I believe, for most of them, they could get by with
: less than 100, but would certainly need super unleaded as a minimum.

True. The high-compression (8.5:1) O-360/O-540's were certificated on 91/96 avgas. The Petersen STC (the
only one applicable to high-compression engines) requires mogas with the appropriate ASTM ratings and to have an
anti-knock-index (Average of Research and Motor octane... "R+M/2") of 91 or higher. When I bought my STC, Petersen
said that even in the high-temp, altitude, CHT setup, they were unable to induce knocking or detonation even with 89.
The certificiation folks wanted a bit of safety margin.

It should also be pointed out that the R+M/2 rating does not directly compare to the avgas lean rating (i.e.
the "91" of the 91/96 or the "100" of 100/130 100LL). The avgas lean rating testing setup more closely resembles the
Motor method of the R+M/2. Typical point spread ("sensitivity" IIRC) is +-4 to 5 points on either side. In other
words, 91 AKI is more like 96 Research, 86 Motor... i.e. a bit dicey given the 91/96 rating of the aviation engine.

That said, I haven't experienced any troubles running hundreds of gallons of 93 AKI through my O-360 180hp...
summer, winter, etc.

-Cory


************************************************** ***********************
* Cory Papenfuss, Ph.D., PPSEL-IA *
* Electrical Engineering *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

[Jay Honeck]

> > As posted before, the head honcho at Dawley Aviation (the exhaust
> > system folks in Burlington, WI) told me personally that running lean of
> > peak has been the best thing that EVER happened to their business.
>
> And has been pointed out in this group previously, he's full of ****.

Hmmm. Let's see. Shall I believe the guy who runs a multi-million
dollar aircraft exhaust system business (and has no incentive to lie to
me), or shall I believe Usenet?

Golly, what a conundrum...

;-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Gig 601XL Builder]

"Matt Barrow" > wrote in message
...
>
> "soxinbox" > wrote in message
> ...
>> If you run your car engine on 80 octane mogas, it will usually run fine.
>> If your car overheats, it will start to knock. If you have 100 octane gas
>> it will start to knock at a higher CHT than if you ran at 80 octane. This
>> is not usually a problem in a car that has a radiator and thermostat to
>> regulate the temperature.
>
> I can't remember seeing anything less than 85 octane car gas since, oh,
> maybe the 60's?
>

Around here the grades on the pump are 83,89 and 93. Here=South & Central
Arkansas.

[Matt Barrow]

"Jay Honeck" > wrote in message
oups.com...
>> > As posted before, the head honcho at Dawley Aviation (the exhaust
>> > system folks in Burlington, WI) told me personally that running lean of
>> > peak has been the best thing that EVER happened to their business.
>>
>> And has been pointed out in this group previously, he's full of ****.
>
> Hmmm. Let's see. Shall I believe the guy who runs a multi-million
> dollar aircraft exhaust system business (and has no incentive to lie to
> me),
Who said he was lying?

> Golly, what a conundrum...

Indeed, when you don't know the difference between "falsehood" and
"mistaken".

English major, huh?

Maybe you can have him explain how he's doing such a great business in when
maybe 5% of the aircraft are being run LOP?

Maybe you can have him explain how that happens when the EGT is symetrical
on either side of peak EGT, and the CHT is actually cooler...much cooler?

> or shall I believe Usenet?

Did he give you as data-intensive an answer as you got on UseNet (complete
with charts and graphs?

Or maybe you can go back and bury your head in the sand.

[Bela P. Havasreti]

On Fri, 12 May 2006 08:42:59 -0500, "Gig 601XL Builder"
<wrDOTgiaconaATcox.net> wrote:

>
>"Matt Barrow" > wrote in message
...
>>
>> "soxinbox" > wrote in message
>> ...
>>> If you run your car engine on 80 octane mogas, it will usually run fine.
>>> If your car overheats, it will start to knock. If you have 100 octane gas
>>> it will start to knock at a higher CHT than if you ran at 80 octane. This
>>> is not usually a problem in a car that has a radiator and thermostat to
>>> regulate the temperature.
>>
>> I can't remember seeing anything less than 85 octane car gas since, oh,
>> maybe the 60's?
>>
>
>Around here the grades on the pump are 83,89 and 93. Here=South & Central
>Arkansas.

I've always wondered why the mogas octane levels are different around
various areas of the US. Where I live (northwest), our mogas is
87, 89 and 92.

Bela P. Havasreti

[Bela P. Havasreti]

On Thu, 11 May 2006 19:01:16 -0700, "Matt Barrow"
> wrote:

>
>"Bela P. Havasreti" > wrote in message
...
>> Perhaps a more useful comparison would be how much
>> lead is/was in 80/87 vs 100LL?
>>
>> Those of use with older, low compression engines that were designed
>> to run on 80/87 may be introducing 4 times the amount of lead into our
>> combustion chambers by running 100LL than the original designers had
>> intended for.
>>
>> 80/87 has a maximum of 0.5 grams of lead per US gallon while 100LL has
>> a maximum of 2.0 grams of lead per US gallon. Unleaded Mogas is...
>> well... Unleaded!
>>
>> In reading about this somewhere (AvWeb? EAA?) I recall words to the
>> effect that the refineries can get up to about 97 octane without any
>> lead, and they only add as much in to get to (or slightly exceed) the
>> 100 octane rating.
>
>This one: http://www.avweb.com/news/columns/182149-1.html

That's it! Thanks for the link (bookmarked it this time).

Bela P. Havasreti

[Matt Barrow]

"Bela P. Havasreti" > wrote in message
...
> On Fri, 12 May 2006 08:42:59 -0500, "Gig 601XL Builder"
> <wrDOTgiaconaATcox.net> wrote:
>
>>
>>"Matt Barrow" > wrote in message
...
>>>
>>> "soxinbox" > wrote in message
>>> ...
>>>> If you run your car engine on 80 octane mogas, it will usually run
>>>> fine.
>>>> If your car overheats, it will start to knock. If you have 100 octane
>>>> gas
>>>> it will start to knock at a higher CHT than if you ran at 80 octane.
>>>> This
>>>> is not usually a problem in a car that has a radiator and thermostat to
>>>> regulate the temperature.
>>>
>>> I can't remember seeing anything less than 85 octane car gas since, oh,
>>> maybe the 60's?
>>>
>>
>>Around here the grades on the pump are 83,89 and 93. Here=South & Central
>>Arkansas.
>
> I've always wondered why the mogas octane levels are different around
> various areas of the US. Where I live (northwest), our mogas is
> 87, 89 and 92.
>

Altitude - higher needs more octane.

[Montblack]

("Matt Barrow" wrote)

"Or maybe you can go back and bury your head in the [corn]."


Montblack

[karl gruber]

>
> Altitude - higher needs more octane.

Altitude-higher needs less octane

Karl
ATP CFI ETC
"Curator" N185KG

[Matt Barrow]

"karl gruber" > wrote in message
...
> >
>> Altitude - higher needs more octane.
>
> Altitude-higher needs less octane
>
Correct -- that's what I get for rewording it three times.

[Matt Barrow]

"Montblack" > wrote in message
...
> ("Matt Barrow" wrote)
>
> "Or maybe you can go back and bury your head in the [corn]."
>
Oh, now that's low (this time of year).

[Jay Masino]

wrote:
> That said, I haven't experienced any troubles running hundreds of gallons of 93 AKI through my O-360 180hp...
> summer, winter, etc.
>
> -Cory

I'd love to be able to, but the Petersen STC for "high" compression Cherokees is
now more than $2500, and we've got ethanol in our gas in Maryland now.

--- Jay


--

Jay Masino "Home is where the critters are"
http://www.JayMasino.com
http://www.OceanCityAirport.com
http://www.oc-Adolfos.com

[Frank Stutzman]

Jay Honeck > wrote:
> Hmmm. Let's see. Shall I believe the guy who runs a multi-million
> dollar aircraft exhaust system business (and has no incentive to lie to
> me), or shall I believe Usenet?

Teledyne Continental and (I think) Lycoming have both gone on record
to say that mogas is damaging to their engines. They are certainly
multi-millon dollar aircraft engine companies and have have no
incentive to lie to you.

Yet you, Jay, are an ardent user of mogas. Who do believe: the engine
companies or Usenet?

I'd ask your exhaust system rebuilder to show you the data. I doubt
he really has any and that he is perpetrating yet another aviation
old wives tale. If he does actually have valid data, I'd wager that
a different conclusion could be drawn from it.

--
Frank Stutzman (who uses both mogas AND LOP operations)
Bonanza N494B "Hula Girl"
Hood River, OR

[Allen]

....
> Jay Honeck > wrote:
>> Hmmm. Let's see. Shall I believe the guy who runs a multi-million
>> dollar aircraft exhaust system business (and has no incentive to lie to
>> me), or shall I believe Usenet?
"Frank Stutzman" > wrote in message

> Teledyne Continental and (I think) Lycoming have both gone on record
> to say that mogas is damaging to their engines. They are certainly
> multi-millon dollar aircraft engine companies and have have no
> incentive to lie to you.

They are also multi-million dollar aircraft engine companies that recommend
against LOP operation. (Unless you are running a FADEC system).

Allen

[Matt Barrow]

"Bela P. Havasreti" > wrote in message
...
>>> In reading about this somewhere (AvWeb? EAA?) I recall words to the
>>> effect that the refineries can get up to about 97 octane without any
>>> lead, and they only add as much in to get to (or slightly exceed) the
>>> 100 octane rating.
>>
>>This one: http://www.avweb.com/news/columns/182149-1.html
>
> That's it! Thanks for the link (bookmarked it this time).
>
Most welcome!!

In another article, Deakin was talking about GAMI running a 375HP Lycoming
540 (the one most prone to detonation) on unleaded 95 octane gas on their
test-stand with their experimental PRISM system with nary a burp. AIR,
they've run TNIO-550's on mogas with the PRISM system, too.

Unfortunately, they're about three years overdue for their hoped for STC.

[Jay Honeck]

> > "Or maybe you can go back and bury your head in the [corn]."

Get it right:

"Or maybe you can go back and bury your head in the [ethanol]."

:-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Matt Barrow]

"Jay Honeck" > wrote in message
oups.com...
>> > "Or maybe you can go back and bury your head in the [corn]."
>
> Get it right:
>
> "Or maybe you can go back and bury your head in the [ethanol]."
>
> :-)

Dammit! Use a STRAW!!

[Allen]

>
> "Allen" > wrote in message
> . com...
>> They are also multi-million dollar aircraft engine companies that
>> recommend against LOP operation. (Unless you are running a FADEC
>> system).

"Matt Barrow" > wrote in message
...
>
> Have they ever shown you or anyone else REAL DATA?
>
> No? Gee, why not?
>
>>
> Yes, like Lycoming who recommends 50ROP. Got any idea what THAT will do to
> your valves, heads, exhaust system?
>
> Oh, and Columbia recommends LOP for it's IO-550'ed 400 model.

Well gee, think of the lure that TCM would have to produce engines for
aircraft manufacturers if they could tout running lean of peak. They don't.
Why not? Warranty costs. Get a clue.

[Javier]

Matt Barrow wrote:
> "Allen" > wrote in message
> . com...
>> ...
>>> Jay Honeck > wrote:
>>>> Hmmm. Let's see. Shall I believe the guy who runs a multi-million
>>>> dollar aircraft exhaust system business (and has no incentive to lie to
>>>> me), or shall I believe Usenet?
>> "Frank Stutzman" > wrote in message
>>
>>> Teledyne Continental and (I think) Lycoming have both gone on record
>>> to say that mogas is damaging to their engines. They are certainly
>>> multi-millon dollar aircraft engine companies and have have no
>>> incentive to lie to you.
>> They are also multi-million dollar aircraft engine companies that
>> recommend against LOP operation. (Unless you are running a FADEC system).
>
> Have they ever shown you or anyone else REAL DATA?
>
> No? Gee, why not?
>
> Yes, like Lycoming who recommends 50ROP. Got any idea what THAT will do to
> your valves, heads, exhaust system?
>
> Oh, and Columbia recommends LOP for it's IO-550'ed 400 model.


Mirage/Malibu models with certain engines need to be ran LOP, per the
POH, too.

From what I've been reading on the Mooney list by Walter Atkinson, LOP
is a Good Thing, and even doable on carbureted engines (one needs to
play with the carb heat setting, an engine analyzer and a carb temp
gauge are de rigueur).

-jav

[Newps]

Bela P. Havasreti wrote:

>>
>>Around here the grades on the pump are 83,89 and 93. Here=South & Central
>>Arkansas.

I think he's mistaken on the 83.

>
>
> I've always wondered why the mogas octane levels are different around
> various areas of the US. Where I live (northwest), our mogas is
> 87, 89 and 92.

The lowest octane that you find in a given area has to do with altitude.
The higher you are the less octane you need. Around here regular is 85.5

[Newps]

Allen wrote:


>
> They are also multi-million dollar aircraft engine companies that recommend
> against LOP operation. (Unless you are running a FADEC system).

Yes, suddenly it's OK to run LOP when you give them $10K for their FADEC.

[Newps]

Allen wrote:


>
> Well gee, think of the lure that TCM would have to produce engines for
> aircraft manufacturers if they could tout running lean of peak. They don't.
> Why not? Warranty costs. Get a clue.

It doesn't matter where you run your engine. If you run it wrong it
will cause warranty claims.

[Allen]

"Newps" > wrote in message
...
>
>
> Allen wrote:
>
>
>>
>> They are also multi-million dollar aircraft engine companies that
>> recommend against LOP operation. (Unless you are running a FADEC
>> system).
>
> Yes, suddenly it's OK to run LOP when you give them $10K for their FADEC.

That is because you have zero control over the fuel-air mixture, they do.

Allen

[Matt Barrow]

"Allen" > wrote in message
. com...
>
>>
>> "Allen" > wrote in message
>> . com...
>>> They are also multi-million dollar aircraft engine companies that
>>> recommend against LOP operation. (Unless you are running a FADEC
>>> system).
>
> "Matt Barrow" > wrote in message
> ...
>>
>> Have they ever shown you or anyone else REAL DATA?
>>
>> No? Gee, why not?
>>
>>>
>> Yes, like Lycoming who recommends 50ROP. Got any idea what THAT will do
>> to your valves, heads, exhaust system?
>>
>> Oh, and Columbia recommends LOP for it's IO-550'ed 400 model.
>
> Well gee, think of the lure that TCM would have to produce engines for
> aircraft manufacturers if they could tout running lean of peak. They
> don't. Why not? Warranty costs. Get a clue.

What warranty? What warranty costs?

You still haven't shown us any DATA, just regurgitating the same BS.

What is the lure that TCM and Lycoming have for running ROP? Oh, just
engines that last 800 hours...maybe. Sure sell a lot of 'em, won't they.
And, hey...if the break, it sure is easy to put a Lycoming into a Bonanza,
or a TCM into a current Cessna, right?

Get a clue yourself. Gullibility is not attractive in adults.

[Allen]

"Matt Barrow" > wrote in message
...
>
> "Allen" > wrote in message
> . com...
>>
>>>
>>> "Allen" > wrote in message
>>> . com...
>>>> They are also multi-million dollar aircraft engine companies that
>>>> recommend against LOP operation. (Unless you are running a FADEC
>>>> system).
>>
>> "Matt Barrow" > wrote in message
>> ...
>>>
>>> Have they ever shown you or anyone else REAL DATA?
>>>
>>> No? Gee, why not?
>>>
>>>>
>>> Yes, like Lycoming who recommends 50ROP. Got any idea what THAT will do
>>> to your valves, heads, exhaust system?
>>>
>>> Oh, and Columbia recommends LOP for it's IO-550'ed 400 model.
>>
>> Well gee, think of the lure that TCM would have to produce engines for
>> aircraft manufacturers if they could tout running lean of peak. They
>> don't. Why not? Warranty costs. Get a clue.
>
> What warranty? What warranty costs?
>
> You still haven't shown us any DATA, just regurgitating the same BS.
>
> What is the lure that TCM and Lycoming have for running ROP? Oh, just
> engines that last 800 hours...maybe. Sure sell a lot of 'em, won't they.
> And, hey...if the break, it sure is easy to put a Lycoming into a Bonanza,
> or a TCM into a current Cessna, right?
>
> Get a clue yourself. Gullibility is not attractive in adults.

Let's see, the company that designed and manufactured the engine says don't
run lean of peak, the aircraft manufacturer (except for a handful of
instances) says don't run lean of peak but Matt Barrow says ok to run lean
of peak. Whom to believe, whom to believe. Talk about being gullible, look
in the mirror.

Don't you think that if running lean of peak would make their engines reach
TBO that TCM wouldn't jump on that in an instant?

[Mark Hansen]

On 05/12/06 11:21, Allen wrote:
> "Matt Barrow" > wrote in message
> ...
>>
>> "Allen" > wrote in message
>> . com...
>>>
>>>>
>>>> "Allen" > wrote in message
>>>> . com...
>>>>> They are also multi-million dollar aircraft engine companies that
>>>>> recommend against LOP operation. (Unless you are running a FADEC
>>>>> system).
>>>
>>> "Matt Barrow" > wrote in message
>>> ...
>>>>
>>>> Have they ever shown you or anyone else REAL DATA?
>>>>
>>>> No? Gee, why not?
>>>>
>>>>>
>>>> Yes, like Lycoming who recommends 50ROP. Got any idea what THAT will do
>>>> to your valves, heads, exhaust system?
>>>>
>>>> Oh, and Columbia recommends LOP for it's IO-550'ed 400 model.
>>>
>>> Well gee, think of the lure that TCM would have to produce engines for
>>> aircraft manufacturers if they could tout running lean of peak. They
>>> don't. Why not? Warranty costs. Get a clue.
>>
>> What warranty? What warranty costs?
>>
>> You still haven't shown us any DATA, just regurgitating the same BS.
>>
>> What is the lure that TCM and Lycoming have for running ROP? Oh, just
>> engines that last 800 hours...maybe. Sure sell a lot of 'em, won't they.
>> And, hey...if the break, it sure is easy to put a Lycoming into a Bonanza,
>> or a TCM into a current Cessna, right?
>>
>> Get a clue yourself. Gullibility is not attractive in adults.
>
> Let's see, the company that designed and manufactured the engine says don't
> run lean of peak, the aircraft manufacturer (except for a handful of
> instances) says don't run lean of peak but Matt Barrow says ok to run lean
> of peak. Whom to believe, whom to believe. Talk about being gullible, look
> in the mirror.
>
> Don't you think that if running lean of peak would make their engines reach
> TBO that TCM wouldn't jump on that in an instant?

Have you read the John Deakin articles on AVWeb? He talks in great length
about LOP operations and why the manufacturers (generally) don't recommend
it in the POHs.

The articles have a lot of data to back up the claims.

Regardless of which camp you're in, they're a very good read.

Best Regards,

[Allen]

"Mark Hansen" > wrote in message
...
> On 05/12/06 11:21, Allen wrote:
>>> "Allen" > wrote in message
>>> . com...
>>>>
>> Let's see, the company that designed and manufactured the engine says
>> don't
>> run lean of peak, the aircraft manufacturer (except for a handful of
>> instances) says don't run lean of peak but Matt Barrow says ok to run
>> lean
>> of peak. Whom to believe, whom to believe. Talk about being gullible,
>> look
>> in the mirror.
>>
>> Don't you think that if running lean of peak would make their engines
>> reach
>> TBO that TCM wouldn't jump on that in an instant?
>
> Have you read the John Deakin articles on AVWeb? He talks in great length
> about LOP operations and why the manufacturers (generally) don't recommend
> it in the POHs.
>
> The articles have a lot of data to back up the claims.
>
> Regardless of which camp you're in, they're a very good read.
>
> Best Regards,

Yes.

[M]

Lower octane autogas is quite common in mountain states where the
elevation is high. Non turbo-charged car engines have a bigger
denotation margin at higher elevation and require less octane.

[Jay Honeck]

> Maybe you can have him explain how he's doing such a great business in when
> maybe 5% of the aircraft are being run LOP?
>
> Maybe you can have him explain how that happens when the EGT is symetrical
> on either side of peak EGT, and the CHT is actually cooler...much cooler?

I believe Dawley's exhaust business is benefiting from people running
INCORRECTLY lean of peak. The problem isn't necessarily running lean
of peak, which most people know should produce cooler (not hotter) EGTs
and CHTs.

The trouble comes with everyone TRYING to run LOP (or, just plain
leanER) to save gas, without the proper instrumentation, technique, or
knowledge.

Heat kills exhaust systems. Dawley has noticed a spike in their sales
since gas prices went through the roof, and they believe it is due to
everyone trying to run LOP. I have no reason to doubt them.

People are saving a few bucks on gas, but are spending a few hundred on
more frequent exhaust system replacement costs. I would imagine this
may translate into other repair costs as well. It's the nature of the
beast.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Newps]

Allen wrote:
> "Newps" > wrote in message
> ...
>
>>
>>Allen wrote:
>>
>>
>>
>>>They are also multi-million dollar aircraft engine companies that
>>>recommend against LOP operation. (Unless you are running a FADEC
>>>system).
>>
>>Yes, suddenly it's OK to run LOP when you give them $10K for their FADEC.
>
>
> That is because you have zero control over the fuel-air mixture, they do.

Which isn't their argument now. They flat out say it isn't good for the
engine period.

[Bela P. Havasreti]

On 12 May 2006 12:00:24 -0700, "M" > wrote:

>Lower octane autogas is quite common in mountain states where the
>elevation is high. Non turbo-charged car engines have a bigger
>denotation margin at higher elevation and require less octane.

So that's why "super" mogas in Florida is 93 octane but only
92 octane in the Seattle area. Thanks everyone for the replies
(usenet is good for something besides arguing about politics
afterall!).

Bela P. Havasreti

[Allen]

"Newps" > wrote in message
. ..
>
>
> Allen wrote:
>> "Newps" > wrote in message
>> ...
>>
>>>
>>>Allen wrote:
>>>
>>>
>>>
>>>>They are also multi-million dollar aircraft engine companies that
>>>>recommend against LOP operation. (Unless you are running a FADEC
>>>>system).
>>>
>>>Yes, suddenly it's OK to run LOP when you give them $10K for their FADEC.
>>
>>
>> That is because you have zero control over the fuel-air mixture, they do.
>
> Which isn't their argument now. They flat out say it isn't good for the
> engine period.

That is correct, because you can't control the fuel flow to all cylinders
precisely enough. The FADEC system will not allow the engine to run in an
condition that will cause damage. If a CHT is too high or EGT too high
guess what happens. It INCREASES the fuel flow to that one cylinder to
bring it down. It can also retard the ignition on that one cylinder only to
correct the condition. It never LEANS further to cool cylinders or EGT
temps.

[Dave Stadt]

"Frank Stutzman" > wrote in message
...
> Jay Honeck > wrote:
>> Hmmm. Let's see. Shall I believe the guy who runs a multi-million
>> dollar aircraft exhaust system business (and has no incentive to lie to
>> me), or shall I believe Usenet?
>
> Teledyne Continental and (I think) Lycoming have both gone on record
> to say that mogas is damaging to their engines. They are certainly
> multi-millon dollar aircraft engine companies and have have no
> incentive to lie to you.
>
> Yet you, Jay, are an ardent user of mogas. Who do believe: the engine
> companies or Usenet?

Just what damage is caused by mogas? I don't believe either company has
ever provided one iota of evidence. It is more the lawyers talking than
anyone that actually knows an engine from a rock.

>
> I'd ask your exhaust system rebuilder to show you the data. I doubt
> he really has any and that he is perpetrating yet another aviation
> old wives tale. If he does actually have valid data, I'd wager that
> a different conclusion could be drawn from it.
>
> --
> Frank Stutzman (who uses both mogas AND LOP operations)
> Bonanza N494B "Hula Girl"
> Hood River, OR
>

[Matt Barrow]

"Jay Honeck" > wrote in message
oups.com...
>> Maybe you can have him explain how he's doing such a great business in
>> when
>> maybe 5% of the aircraft are being run LOP?
>>
>> Maybe you can have him explain how that happens when the EGT is
>> symetrical
>> on either side of peak EGT, and the CHT is actually cooler...much cooler?
>
> I believe Dawley's exhaust business is benefiting from people running
> INCORRECTLY lean of peak.

Considering that most engines will shake themselves to death before they're
much leaner than peak, that's a bit of a stretch.

If someone is leaning incorrectly, attemping LOP will give warnings before
they get there. Blaming it BLINDLY on LOP is stupid. If he wants to say
"Incorrect leaning procedures", that's what he should say. Again, for YEARS
the standard procedure was right at peak EGT, as in the standard dogma, "I
lean to peak then enrich a bit". Well, that kept the engine shops busy doing
jugs and heads. It kept the maintenance people busy doing fouled plugs and
valves.

Think of someone you drove with who was driving a stick shift, but who
didn't give it enough gas before engaging the clutch, or who rode the
clutch; does that mean stick shifts are bad because they'd wear out the
clutch really soon?


> The problem isn't necessarily running lean
> of peak, which most people know should produce cooler (not hotter) EGTs
> and CHTs.

Most people DON'T know that LOP is cooler. AAMOF, on the A&P tests, the
correct answer to "What will too lean a mixture produce" define the problem
just the opposite (ie, higher CHT temps).

>
> The trouble comes with everyone TRYING to run LOP (or, just plain
> leanER) to save gas, without the proper instrumentation, technique, or
> knowledge.

SInce most people are flying rentals/club aircraft which are rented WET, I
really wonder how many are trying ot overlean without the proper equipment
and instrumentation. Even so, having the right "stuff", LOP procedures is
different (ie, going from full rich to LOP in 2-3 seconds, not the several
seconds up to a minute that some people use in adjusting the mixture.

>
> Heat kills exhaust systems. Dawley has noticed a spike in their sales
> since gas prices went through the roof, and they believe it is due to
> everyone trying to run LOP. I have no reason to doubt them.

Well, when people were running in the "Red Zone", that would have been a
boon to his business since ROP is hotter. Much hotter.

>
> People are saving a few bucks on gas, but are spending a few hundred on
> more frequent exhaust system replacement costs. I would imagine this
> may translate into other repair costs as well. It's the nature of the
> beast.

As above...but no doubt, many have changed from 200ROP over to peak to
20LOP, still in the "Red Zone". But again, if he doesn't know the difference
between LOP and merely bad leaning technique, he should qualify his
statement or else he comes off a fool.

Just to show how stupid the FAA exams are and the naiveté of many of they
people they "spawned", see what Mike Busch has to say:
http://www.avweb.com/news/columns/182135-1.html

Now, you can take that stuff as an "Internet Legend" because we all know
that what comes out of the engine manufacturers Legal or Sales & Marketing
departments is GOSPEL (everybody say "Amen"!!).


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

[Matt Barrow]

"Bela P. Havasreti" > wrote in message
...

>>> In reading about this somewhere (AvWeb? EAA?) I recall words to the
>>> effect that the refineries can get up to about 97 octane without any
>>> lead, and they only add as much in to get to (or slightly exceed) the
>>> 100 octane rating.
>>
>>This one: http://www.avweb.com/news/columns/182149-1.html
>
> That's it! Thanks for the link (bookmarked it this time).
>
Hell, pop over to "Printer Friendly Page" and save it as a MHT file to your
hard drive (if using Windows Exploder).


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

[Matt Barrow]

"Newps" > wrote in message
...
>
>
> Allen wrote:
>
>
>>
>> Well gee, think of the lure that TCM would have to produce engines for
>> aircraft manufacturers if they could tout running lean of peak. They
>> don't. Why not? Warranty costs. Get a clue.
>
> It doesn't matter where you run your engine. If you run it wrong it will
> cause warranty claims.

And he never evidently heard of the "Legal Department" that would "frown" on
them changing their procedures after all these years...

[Matt Barrow]

"Allen" > wrote in message
. com...
>
>>>>
>>>> Have they ever shown you or anyone else REAL DATA?
>>>>
>>>> No? Gee, why not?
>>>>
>>>>>
>>>> Yes, like Lycoming who recommends 50ROP. Got any idea what THAT will do
>>>> to your valves, heads, exhaust system?
>>>>
>>>> Oh, and Columbia recommends LOP for it's IO-550'ed 400 model.
>>>
>>> Well gee, think of the lure that TCM would have to produce engines for
>>> aircraft manufacturers if they could tout running lean of peak. They
>>> don't. Why not? Warranty costs. Get a clue.
>>
>> What warranty? What warranty costs?
>>
>> You still haven't shown us any DATA, just regurgitating the same BS.
>>
>> What is the lure that TCM and Lycoming have for running ROP? Oh, just
>> engines that last 800 hours...maybe. Sure sell a lot of 'em, won't they.
>> And, hey...if the break, it sure is easy to put a Lycoming into a
>> Bonanza, or a TCM into a current Cessna, right?
>>
>> Get a clue yourself. Gullibility is not attractive in adults.
>
> Let's see, the company that designed and manufactured the engine says
> don't run lean of peak, the aircraft manufacturer (except for a handful of
> instances) says don't run lean of peak but Matt Barrow says ok to run lean
> of peak. Whom to believe, whom to believe. Talk about being gullible,
> look in the mirror.

No, Matt Barrow doesn't say it (Allen is evidently reading comp challenged
as well as gullible).

>
> Don't you think that if running lean of peak would make their engines
> reach TBO that TCM wouldn't jump on that in an instant?

No, I don't. See remarks about gullibility.

[Matt Barrow]

"Allen" > wrote in message
om...
>
> "Mark Hansen" > wrote in message
> ...
>> On 05/12/06 11:21, Allen wrote:
>>>> "Allen" > wrote in message
>>>> . com...
>>>>>
>>> Let's see, the company that designed and manufactured the engine says
>>> don't
>>> run lean of peak, the aircraft manufacturer (except for a handful of
>>> instances) says don't run lean of peak but Matt Barrow says ok to run
>>> lean
>>> of peak. Whom to believe, whom to believe. Talk about being gullible,
>>> look
>>> in the mirror.
>>>
>>> Don't you think that if running lean of peak would make their engines
>>> reach
>>> TBO that TCM wouldn't jump on that in an instant?
>>
>> Have you read the John Deakin articles on AVWeb? He talks in great length
>> about LOP operations and why the manufacturers (generally) don't
>> recommend
>> it in the POHs.
>>
>> The articles have a lot of data to back up the claims.
>>
>> Regardless of which camp you're in, they're a very good read.
>>
>> Best Regards,
>
> Yes.

Glad you agree, now go and COMPREHEND them and all their contexts and
caveats, not just READ them. Then compare Deakins' data to what you beloved
manufacturers have spewed, and you just regurgitate.

[Matt Barrow]

"Javier" > wrote in message
...
> Matt Barrow wrote:
>> "Allen" > wrote in message
>> . com...
>>> ...
>>>> Jay Honeck > wrote:
>>>>> Hmmm. Let's see. Shall I believe the guy who runs a multi-million
>>>>> dollar aircraft exhaust system business (and has no incentive to lie
>>>>> to
>>>>> me), or shall I believe Usenet?
>>> "Frank Stutzman" > wrote in message
>>>
>>>> Teledyne Continental and (I think) Lycoming have both gone on record
>>>> to say that mogas is damaging to their engines. They are certainly
>>>> multi-millon dollar aircraft engine companies and have have no
>>>> incentive to lie to you.
>>> They are also multi-million dollar aircraft engine companies that
>>> recommend against LOP operation. (Unless you are running a FADEC
>>> system).
>>
>> Have they ever shown you or anyone else REAL DATA?
>>
>> No? Gee, why not?
>>
>> Yes, like Lycoming who recommends 50ROP. Got any idea what THAT will do
>> to your valves, heads, exhaust system?
>>
>> Oh, and Columbia recommends LOP for it's IO-550'ed 400 model.
>
>
> Mirage/Malibu models with certain engines need to be ran LOP, per the POH,
> too.

Recall, too, that the earlier Malibu's ran into problems because pilots were
"chicken" to run LOP and the engine baffeling was quite suboptmal.

>
> From what I've been reading on the Mooney list by Walter Atkinson, LOP is
> a Good Thing, and even doable on carbureted engines (one needs to play
> with the carb heat setting, an engine analyzer and a carb temp gauge are
> de rigueur).

A touch of Carb heat and the throttle cracked ever so slightly. It creates
turbulence in the intake system that evens things out rather nicely. I
guess it, unfortunately, doesn't work with many of the 182's whose carbs are
just a nightmare. (??)

[Matt Barrow]

"Allen" > wrote in message
. com...
>
> "Newps" > wrote in message
> . ..
>>
>>
>> Allen wrote:
>>> "Newps" > wrote in message
>>> ...
>>>
>>>>
>>>>Allen wrote:
>>>>
>>>>
>>>>
>>>>>They are also multi-million dollar aircraft engine companies that
>>>>>recommend against LOP operation. (Unless you are running a FADEC
>>>>>system).
>>>>
>>>>Yes, suddenly it's OK to run LOP when you give them $10K for their
>>>>FADEC.
>>>
>>>
>>> That is because you have zero control over the fuel-air mixture, they
>>> do.
>>
>> Which isn't their argument now. They flat out say it isn't good for the
>> engine period.
>
> That is correct, because you can't control the fuel flow to all cylinders
> precisely enough.

Well, so lets put in $8000 for a FADEC instead of $1000 for GAMI's. Yeah,
that's a great deal.

> The FADEC system will not allow the engine to run in an condition that
> will cause damage. If a CHT is too high or EGT too high guess what
> happens. It INCREASES the fuel flow to that one cylinder to bring it
> down.

FADEC can't adjust one cylinders fuel flow.

> It can also retard the ignition on that one cylinder only to correct the
> condition. It never LEANS further to cool cylinders or EGT temps.

What a marvel of Rube Goldberg engineering.

So, are they going to increase their warranties from nothing to something
now?

[Matt Barrow]

"Dave Stadt" > wrote in message
om...
>
> "Frank Stutzman" > wrote in message
> ...
>> Jay Honeck > wrote:
>>> Hmmm. Let's see. Shall I believe the guy who runs a multi-million
>>> dollar aircraft exhaust system business (and has no incentive to lie to
>>> me), or shall I believe Usenet?
>>
>> Teledyne Continental and (I think) Lycoming have both gone on record
>> to say that mogas is damaging to their engines. They are certainly
>> multi-millon dollar aircraft engine companies and have have no
>> incentive to lie to you.
>>
>> Yet you, Jay, are an ardent user of mogas. Who do believe: the engine
>> companies or Usenet?
>
> Just what damage is caused by mogas?

The same problem that some cars had; hose, gaskets, etc., something like
that?

> I don't believe either company has ever provided one iota of evidence. It
> is more the lawyers talking than anyone that actually knows an engine from
> a rock.

Well, that last is ALL IMPORTANT given out litigious society.

[.Blueskies.]

"Bela P. Havasreti" > wrote in message ...
> On 12 May 2006 12:00:24 -0700, "M" > wrote:
>
>>Lower octane autogas is quite common in mountain states where the
>>elevation is high. Non turbo-charged car engines have a bigger
>>denotation margin at higher elevation and require less octane.
>
> So that's why "super" mogas in Florida is 93 octane but only
> 92 octane in the Seattle area. Thanks everyone for the replies
> (usenet is good for something besides arguing about politics
> afterall!).
>
> Bela P. Havasreti


Both Seattle and Florida are basically at sea level. The lower octane is not explained by altitude difference in this
case....

[Matt Barrow]

"Jay Honeck" > wrote in message
ups.com...
>> > From what I've been reading on the Mooney list by Walter Atkinson, LOP
>> > is
>> > a Good Thing, and even doable on carbureted engines (one needs to play
>> > with the carb heat setting, an engine analyzer and a carb temp gauge
>> > are
>> > de rigueur).
>>
>> A touch of Carb heat and the throttle cracked ever so slightly. It
>> creates
>> turbulence in the intake system that evens things out rather nicely.
>
> Care to expand on that?

http://www.avweb.com/news/columns/182085-1.html

"Carbureted Engines, and Fixed-Pitch Props
The single most-asked question I've had from these engine management columns
has been some wistful variant of, "But what about my 182, which has a
carbureted engine?" Or, "What about my 172, with its fixed-pitch prop?"

Folks, I'm really sorry, there's just not that much that can be done, beyond
a few simple tips that have been commonly used for years, like leaning on
the ground (see below).

Here's another tip for carbureted engines only. When operating at full
throttle, it is often helpful to back off on the throttle until you see just
the tiniest drop in MP (if you have a MP gauge, otherwise look for the
slightest drop in RPM), and leave it there instead of fully open. That cocks
the throttle plate just enough to set up a slightly turbulent flow, and that
helps mix the fuel and air for better combustion. A touch of carburetor heat
may help, too.

But I've flown a couple of 182s that are simply hopeless, and I'm tempted
just to leave the mixture full rich and forget it. Pity, the Skylane is a
marvelous airplane, but that TCM O-470 engine has the worst mixture
distribution of any powerplant on the planet.

If you're fortunate to have an all-cylinder engine monitor on a carbureted
engine, see if you can operate lean enough to get all cylinders lean-of-peak
(LOP) without the engine jumping off its mounts from vibration. I haven't
seen one that would yet, but there may well be some engines that will do it.
If so, some of this column may be helpful.

While the knowledge of these things may be helpful in a general way for
everyone who flies, it is only the high-performance, fuel-injected engines
that allow some of the more sophisticated techniques. Even on those, it
almost always takes GAMIjectors to make these tricks work well enough to use
them at all. This is the primary reason you have not seen some of this
information in the past - it simply hasn't been very useful, and there's
been no need for it.

Once again, this column will refer entirely to normally-aspirated engines,
unless otherwise noted. Yes, yes, I know, there are two or three turbo
owners out there who want me to do a column for them, and I'll get to it,
one day, I promise (but I'm not saying when!)"

[.Blueskies.]

"Bob Fry" > wrote in message ...
>>>>>> "MB" == Montblack > writes:
>
> MB> What would your unleaded fuel of choice be?
>
> Good old 80/87. But that's not coming back.


Uhhh, 80/67 had lead in it....

[A. Smith]

"Matt Barrow" > wrote in message
...
>>>> "Newps" > wrote in message
>>>> ...
>>>>
>>>>>
>>>>>Allen wrote:
>>>>>
>>>>>
>>>>>
>>>>>>They are also multi-million dollar aircraft engine companies that
>>>>>>recommend against LOP operation. (Unless you are running a FADEC
>>>>>>system).
>>>>>
>>>>>Yes, suddenly it's OK to run LOP when you give them $10K for their
>>>>>FADEC.
>>>>
>>>>
>>>> That is because you have zero control over the fuel-air mixture, they
>>>> do.
>>>
>>> Which isn't their argument now. They flat out say it isn't good for the
>>> engine period.
>>
>> That is correct, because you can't control the fuel flow to all cylinders
>> precisely enough.
>
> Well, so lets put in $8000 for a FADEC instead of $1000 for GAMI's. Yeah,
> that's a great deal.
>
>> The FADEC system will not allow the engine to run in an condition that
>> will cause damage. If a CHT is too high or EGT too high guess what
>> happens. It INCREASES the fuel flow to that one cylinder to bring it
>> down.
>
> FADEC can't adjust one cylinders fuel flow.

You are absolutely wrong, it can and does. Time to do your homewrk and try
to comprehend, gullyboy.


>
>> It can also retard the ignition on that one cylinder only to correct the
>> condition. It never LEANS further to cool cylinders or EGT temps.
>
> What a marvel of Rube Goldberg engineering.
>
> So, are they going to increase their warranties from nothing to something
> now?
>

Sounds like you have this aircraft engine thing figured out. Maybe instead
of building cheap houses you should be building cheap aircraft engines.

[Matt Barrow]

"Jay Honeck" > wrote in message
oups.com...
>> Maybe you can have him explain how he's doing such a great business in
>> when
>> maybe 5% of the aircraft are being run LOP?
>>
>> Maybe you can have him explain how that happens when the EGT is
>> symetrical
>> on either side of peak EGT, and the CHT is actually cooler...much cooler?
>
> I believe Dawley's exhaust business is benefiting from people running
> INCORRECTLY lean of peak.

They're probably wrong on BOTH sides of peak. Pilots have been chewing up
engines long before GAMI reinstituted the "LOP craze".

[Matt Barrow]

"A. Smith" > wrote in message
. com...
>
> "Matt Barrow" > wrote in message
>>
>>> The FADEC system will not allow the engine to run in an condition that
>>> will cause damage. If a CHT is too high or EGT too high guess what
>>> happens. It INCREASES the fuel flow to that one cylinder to bring it
>>> down.
>>
>> FADEC can't adjust one cylinders fuel flow.
>
> You are absolutely wrong, it can and does. Time to do your homewrk and
> try to comprehend, gullyboy.

Cite? (that means you posta link, AKA a URL, not just barf something you
read in an advertisement.)

>>
>>> It can also retard the ignition on that one cylinder only to correct the
>>> condition. It never LEANS further to cool cylinders or EGT temps.
>>
>> What a marvel of Rube Goldberg engineering.
>>
>> So, are they going to increase their warranties from nothing to something
>> now?
>>
>
> Sounds like you have this aircraft engine thing figured out.

Nope, but some experts who actually did tests on a 128 channel test stand
did.

Wrong again. So why not go abck to 2nd grade and relearn "reading
comprehension".



> Maybe instead of building cheap houses you should be building cheap
> aircraft engines.

The more you try your elementary school intimidation, the more you show just
how full of **** you are.

Maybe you should learn to analyze, rather than just puke back the manual ala
high school.

Face it, all you "know" is what some self-proclaimed expert and the FAA
shoved down your throat and you were too chicken to question it.

Oh, and your wonderful TCM and Lycomings that haven't been able to go past
800 hours without a TOH, yes, their advice has really worked well. And their
warranties are the epitome of honorable adherence to a contract.

So go back and read the Flying Mag ads. Punk!

[Matt Barrow]

"A. Smith" > wrote in message
. com...
>
> "Matt Barrow" > wrote in message
> ...
> Sounds like you have this aircraft engine thing figured out. Maybe
> instead of building cheap houses you should be building cheap aircraft
> engines.

Hey ****brains, my structural warranty claims, per unit, are one-third what
Richmond, US Home, and several others are. So evidently you know as much
about construction as you do about engines. Go back and read your magazine
ads.


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

[Newps]

Jay Honeck wrote:

>>A touch of Carb heat and the throttle cracked ever so slightly. It creates
>>turbulence in the intake system that evens things out rather nicely.

The Cessna Pilots Assoc has been teaching that for years. You fly with
whatever amount of carb heat gives you a carb temp of about 40-45
degrees. Helps to even out the mixture too.

[A. Smith]

"Matt Barrow" > wrote in message
...
>
> "A. Smith" > wrote in message
> . com...
>>
>> "Matt Barrow" > wrote in message
>> ...
>> Sounds like you have this aircraft engine thing figured out. Maybe
>> instead of building cheap houses you should be building cheap aircraft
>> engines.
>
> Hey ****brains, my structural warranty claims, per unit, are one-third
> what Richmond, US Home, and several others are. So evidently you know as
> much about construction as you do about engines. Go back and read your
> magazine ads.
> --
> Matt

Ah, profanity, the last resort of the mentally challenged. Maybe you should
take some time and collect your thoughts so you can reply in one post. Do
your own research, I have and I have seen FADEC in action. It works.

[RST Engineering]

Uhhh, no it didn't. It was allowed a MAXIMUM of 0.5 ml / gallon of TEL, but
from the '50s on, the actual TEL count was zero in 80.

Jim



".Blueskies." > wrote in message
. net...
>
> "Bob Fry" > wrote in message
> ...
>>>>>>> "MB" == Montblack > writes:
>>
>> MB> What would your unleaded fuel of choice be?
>>
>> Good old 80/87. But that's not coming back.
>
>
> Uhhh, 80/67 had lead in it....
>

[[email protected]]

..Blueskies. > wrote:

> "Bela P. Havasreti" > wrote in message ...
> > On 12 May 2006 12:00:24 -0700, "M" > wrote:
> >
> >>Lower octane autogas is quite common in mountain states where the
> >>elevation is high. Non turbo-charged car engines have a bigger
> >>denotation margin at higher elevation and require less octane.
> >
> > So that's why "super" mogas in Florida is 93 octane but only
> > 92 octane in the Seattle area. Thanks everyone for the replies
> > (usenet is good for something besides arguing about politics
> > afterall!).
> >
> > Bela P. Havasreti


> Both Seattle and Florida are basically at sea level. The lower octane is not explained by altitude difference in this
> case....

Most of Florida is close to sea level.

You don't have to go far from downtown Seattle to be at 6000 feet.

--
Jim Pennino

Remove .spam.sux to reply.

[RST Engineering]

If you'd just get the operation, you and Mary wouldn't have to USE
conundrums.

Jim


>
> Golly, what a conundrum...
>

[RST Engineering]

<Switching to courtroom mode>

"So, Teledyne Director Of Engineering, would you please tell the court why
you recommended exceessive leaning and poor quality automobile fuel when we
have sworn testimony that it was this lethal combination that caused this
poor widow and her children to lose a husband and father?"

It sure as hell wasn't for engineering reasons that they made these
pronouncements.

>mode off<

Jim



>> Teledyne Continental and (I think) Lycoming have both gone on record
>> to say that mogas is damaging to their engines. They are certainly
>> multi-millon dollar aircraft engine companies and have have no
>> incentive to lie to you.
>
> They are also multi-million dollar aircraft engine companies that
> recommend against LOP operation. (Unless you are running a FADEC system).
>
> Allen
>

[Bela P. Havasreti]

On Sat, 13 May 2006 16:15:01 GMT, wrote:

>.Blueskies. > wrote:
>
>> "Bela P. Havasreti" > wrote in message ...
>> > On 12 May 2006 12:00:24 -0700, "M" > wrote:
>> >
>> >>Lower octane autogas is quite common in mountain states where the
>> >>elevation is high. Non turbo-charged car engines have a bigger
>> >>denotation margin at higher elevation and require less octane.
>> >
>> > So that's why "super" mogas in Florida is 93 octane but only
>> > 92 octane in the Seattle area. Thanks everyone for the replies
>> > (usenet is good for something besides arguing about politics
>> > afterall!).
>> >
>> > Bela P. Havasreti
>
>
>> Both Seattle and Florida are basically at sea level. The lower octane is not explained by altitude difference in this
>> case....
>
>Most of Florida is close to sea level.
>
>You don't have to go far from downtown Seattle to be at 6000 feet.

True. I live at 466 feet (Crest Airpark / S36). I can be at 3000
feet (in my car) within a 25-30 minute drive.

Bela P. Havasreti

[.Blueskies.]

"RST Engineering" > wrote in message .. .
> Uhhh, no it didn't. It was allowed a MAXIMUM of 0.5 ml / gallon of TEL, but from the '50s on, the actual TEL count
> was zero in 80.
>
> Jim
>

Thanks Jim. That's the first I had heard that...but it was not declared as no-lead fuel, so the post asking for what was
the favorite unleaded fuel was a loaded question, eh?

[Aaron Coolidge]

wrote:

: Most of Florida is close to sea level.

I think the highest elevation in Florida is 120-ish feet? I think that's
what the sectional shows.

--
Aaron C.

[Aaron Coolidge]

Jay Honeck > wrote:

:> A touch of Carb heat and the throttle cracked ever so slightly. It creates
:> turbulence in the intake system that evens things out rather nicely.

: Care to expand on that?

Boy, I'm ever so worried to jump into a religious shouting match. But...

When I flew the Cherokee 180, carb'd O-360 or course, I could run LOP with
carb heat turned up. I could use the mix to slow the engine down until
it wasn't producing any useful power. It ran smoothly during this. Without
carb heat it would let you know if you went too far LOP.
I can't repeat these experiments; I'm sure the guy who owns my plane now
would be upset!
--
Aaron C.

[Jay Honeck]

> Here's another tip for carbureted engines only. When operating at full
> throttle, it is often helpful to back off on the throttle until you see just
> the tiniest drop in MP (if you have a MP gauge, otherwise look for the
> slightest drop in RPM), and leave it there instead of fully open. That cocks
> the throttle plate just enough to set up a slightly turbulent flow, and that
> helps mix the fuel and air for better combustion. A touch of carburetor heat
> may help, too.

Using our JPI EDM700 engine analyzer as our guide, we usually can get
all 6 cylinders within 70 degrees of one another using the "pull the
throttle back a hair" method at altitudes from 4500 to 8500 feet.

At full throttle, we're lucky to get them within 150 degrees of
matched.

Never tried the carb heat thing. We don't have a carb temperature
gauge.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Matt Barrow]

"Aaron Coolidge" > wrote in message
...
> Jay Honeck > wrote:
>
> :> A touch of Carb heat and the throttle cracked ever so slightly. It
> creates
> :> turbulence in the intake system that evens things out rather nicely.
>
> : Care to expand on that?
>
> Boy, I'm ever so worried to jump into a religious shouting match. But...

Is it "religious", or religion [anecdote (my mechanc says...,the
manufacturers say without supporting evidence], blind faith [redundant]) vs
science (graphs, charts test stand data)?

[nrp]

A couple of points:

1) My copy of ASTM spec D910 page 0539 states that the allowable TEL
content of 100LL avgas is 2 milliliters per gallon NOT 2 grams per
gallon. This means there will be over 1/3rd pound of lead in an 80
gallon tank of 100LL, plus about 1/5th pound of ethlylene dibromide
scavenging agent.

2) My muffler "failures" were from the internal flame tubes, which
must be present and in reasonable condition if they were originally
present when new, but are not required on later mufflers that did not
have the internal flame tubes. We did a proctoscope exam with a small
flashlight at annual to verify their condition. Our engine was run
about 50 deg rich of peak, or so we thought as we had only a single EGT
probe. There was little engine roughness though if the mixture was
leaned further. Manifold pressure was set to 21 inches for cruise,
less at higher altitudes.

I suspect many 172s were just run until the flame tubes were all gone
out the tailpipe.

[Matt Barrow]

"nrp" > wrote in message
oups.com...
>A couple of points:
>
> 1) My copy of ASTM spec D910 page 0539 states that the allowable TEL
> content of 100LL avgas is 2 milliliters per gallon NOT 2 grams per
> gallon. This means there will be over 1/3rd pound of lead in an 80
> gallon tank of 100LL, plus about 1/5th pound of ethlylene dibromide
> scavenging agent.

Aside from the curiousity of mixing gallons and metric measurments, 2
gr/gallon is 160 grams in an 80 gallon tank. 160/454=0.3524 lbs, so it's
virtually the same thing. SAW, 160 gr in a tank that holds 36,320 grams, 1/3
lb in a tank holding 480 lbs.

[nrp]

It is close, as TEL is only about 2/3 lead by weight. The molecular
weight of TEL is 323 according to my chemistry book, and the tetraethyl
part is about 116. The net numbers work out as you indicated. The
spcific density of TEL is 1.659 gm/ml.

[M]

That's indeed quite a bit, huh? If I take a 1/3lb lead ball to a C-206
flyer and tell him that's how much lead there is in his full tanks, I
bet he'll be surprised.


nrp wrote:
> A couple of points:
>
> 1) My copy of ASTM spec D910 page 0539 states that the allowable TEL
> content of 100LL avgas is 2 milliliters per gallon NOT 2 grams per
> gallon. This means there will be over 1/3rd pound of lead in an 80
> gallon tank of 100LL, plus about 1/5th pound of ethlylene dibromide
> scavenging agent.
>
>

[Matt Barrow]

"M" > wrote in message
ups.com...
>
> That's indeed quite a bit, huh? If I take a 1/3lb lead ball to a C-206
> flyer and tell him that's how much lead there is in his full tanks, I
> bet he'll be surprised.
>
How big do you think that ball would be?

[[email protected]]

Matt Barrow > wrote:

> "M" > wrote in message
> ups.com...
> >
> > That's indeed quite a bit, huh? If I take a 1/3lb lead ball to a C-206
> > flyer and tell him that's how much lead there is in his full tanks, I
> > bet he'll be surprised.
> >
> How big do you think that ball would be?

Roughly somewhere between the size of a candy jaw breaker and a big
marble (I know there is a name for the big ones, but since I lost
all my marbles, I can't remember what it is).

--
Jim Pennino

Remove .spam.sux to reply.

[Montblack]

("Matt Barrow" wrote)
>> That's indeed quite a bit, huh? If I take a 1/3lb lead ball to a C-206
>> flyer and tell him that's how much lead there is in his full tanks, I bet
>> he'll be surprised.

> How big do you think that ball would be?


"I know, I know. Me. Me. Call on Me!"

http://www.tesarta.com/www/resources/library/weights.html
Lead:
[Cubic foot = 1,728 cubic inches]
710 lbs / cubic foot
1 lb. = 2.43 cubic inchs of lead
x 0.33 lbs. = 0.8 c.i. (cubic inches of lead)

http://www.1728.com/diam.htm
Volume of a sphere ..."I knew where to look it up!"

1.15 inches [Diameter] seems to be close for 0.8 cubic inches.

A 25 cent [Quarter] measures 92% of an inch across. About 15/16 - not quite
an inch. (I squinted because I needed 0.92! <g>)

..92 [Diameter] into the sphere equation = 0.4 c.i. (x 2) = 0.8 c.i.

So, two spheres, each with a diameter of a 25 cent [Quarter] = 0.8 cubic
inches ...which = 1/3 lb of lead. One lead ball for each side!


Montblack
Time for Gym. Heading outside for my 3 mile walk....

[Matt Barrow]

"Montblack" > wrote in message
...
> ("Matt Barrow" wrote)
>>> That's indeed quite a bit, huh? If I take a 1/3lb lead ball to a C-206
>>> flyer and tell him that's how much lead there is in his full tanks, I
>>> bet he'll be surprised.
>
>> How big do you think that ball would be?
>
>
> "I know, I know. Me. Me. Call on Me!"
>
> http://www.tesarta.com/www/resources/library/weights.html
> Lead:
> [Cubic foot = 1,728 cubic inches]
> 710 lbs / cubic foot
> 1 lb. = 2.43 cubic inchs of lead
> x 0.33 lbs. = 0.8 c.i. (cubic inches of lead)
>
> http://www.1728.com/diam.htm
> Volume of a sphere ..."I knew where to look it up!"
>
> 1.15 inches [Diameter] seems to be close for 0.8 cubic inches.
>
> A 25 cent [Quarter] measures 92% of an inch across. About 15/16 - not
> quite an inch. (I squinted because I needed 0.92! <g>)
>
> .92 [Diameter] into the sphere equation = 0.4 c.i. (x 2) = 0.8 c.i.
>
> So, two spheres, each with a diameter of a 25 cent [Quarter] = 0.8 cubic
> inches ...which = 1/3 lb of lead. One lead ball for each side!
>
In the words of Don Rickles, "Very good; you win a cookie!" :~)

[Jay Honeck]

> "I know, I know. Me. Me. Call on Me!"
>
> http://www.tesarta.com/www/resources/library/weights.html
> Lead:
> [Cubic foot = 1,728 cubic inches]
> 710 lbs / cubic foot
> 1 lb. = 2.43 cubic inchs of lead
> x 0.33 lbs. = 0.8 c.i. (cubic inches of lead)
>
> http://www.1728.com/diam.htm
> Volume of a sphere ..."I knew where to look it up!"
>
> 1.15 inches [Diameter] seems to be close for 0.8 cubic inches.
>
> A 25 cent [Quarter] measures 92% of an inch across. About 15/16 - not quite
> an inch. (I squinted because I needed 0.92! <g>)
>
> .92 [Diameter] into the sphere equation = 0.4 c.i. (x 2) = 0.8 c.i.
>
> So, two spheres, each with a diameter of a 25 cent [Quarter] = 0.8 cubic
> inches ...which = 1/3 lb of lead. One lead ball for each side!

So there you have it. We can now legitimately claim that using
unleaded Mogas increases your useful load, too!

:-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Montblack]

("Matt Barrow" wrote)
>> So, two spheres, each with a diameter of a 25 cent [Quarter] = 0.8 cubic
>> inches ...which = 1/3 lb of lead. One lead ball for each side!

> In the words of Don Rickles, "Very good; you win a cookie!" :~)


How big's the cookie?


Montblack
Radius is all I need... <g>

[Dave Butler]

Montblack wrote:
> ("Matt Barrow" wrote)
>
>>> So, two spheres, each with a diameter of a 25 cent [Quarter] = 0.8
>>> cubic inches ...which = 1/3 lb of lead. One lead ball for each side!
>
>
>> In the words of Don Rickles, "Very good; you win a cookie!" :~)
>
>
>
> How big's the cookie?

....and what's the lead content?

[Montblack]

("Dave Butler" wrote)
>> How big's the cookie?

> ...and what's the lead content?


Hmm? I thought, in cookies, Pb stood for peanut butter. Drat!


Montblack
"And we talked about some old times
And we drank ourselves some beers
Still crazy afler all these years
Oh, still crazy after all these years"