Avgas 100/130 sellers?

[Exhaustgases]

Anyhow,
Originally Posted by Exhaustgases
So question, ya say lead lubes the valves and or seats? Where is the frictional movement in that interface that needs lubrication, ... what is there to cushion?...

((((Lead lubes the valve guides a bit on some older simple valvle-guide designs,)))) Funny valve guides have not changed since those days, and unleaded gas is used with them. Its an ever so slight oil film and material hardness and differences. Lead does not lube valve guides especially now.



((((but the main thing being protected is valve seats. Now valves do rotate very slightly which is why they wear evenly ))))) after they contact there is no rotation.

(((micro weld when hot))))) maybe micro weld, but the HOT Is correct, and that is the main function of TEL to cool. Proven by tests done years ago on an aircooled VW, monitoring cylinder head temps. TEL ran extremely cooler than unleaded did, and was a very small percentage of TEL.

[/quote]

 

[CT8]

Valves can rotate.

 

[CT8]

Turbines are spendy as compared to a recip engine for the weekend plane enthusiast no?

 

[Exhaustgases]

Originally Posted by CT8
Valves can rotate.

I know they do I've watched them do it, and some engines have a rotator to facilitate it. But not when they are closed / seated and loaded by spring pressure or gas pressure, they do after or before they are seated.

 

[Cujet]

Originally Posted by CT8
Turbines are spendy as compared to a recip engine for the weekend plane enthusiast no?


Absolutely! Gas turbine engines are stupidly expensive. And, quite simply, small aviation based gas turbines can't compete with even the worst piston engines with regard to fuel efficiency.

I own and fly a 177RG with a 200HP 4 cyl Lycoming engine. A factory engine overhaul can cost $37K and lasts 2000 hours. Over that 2000 hours, it will burn about $125,000 worth of fuel.

Let's disregard what a hypothetical 200HP turbine might cost, and consider it will consumes 20GPH. Even with the jet fuel cost savings, you are still at $200K over that same 2000 hours.

FYI, there is a Cessna 210 with a turbine. It's cost is 1.15m, and the hot section inspection is due at 1750 hours, for a cost of $60,000.


You can see why the light aircraft market never transitioned over to turbines. It becomes unfordable very quickly. As cost per flight hour goes from $80 to many hundreds in an instant.

 

[Exhaustgases]

Ethylene Dibromide, is to gasify the tel so it can exhaust from the cylinder. It is undesirable to have it(tel) remaining and attaching to especially the spark plugs. Yes in some cases valves can rotate, and that is most always at higher speeds, do to spring fluctuations. The temperature of the valves and flame passing around the seat and valve along with the scavenger won't allow lead attachment, any deposites are lead bromide that gasifys at around 200 to 250 C it deposites on colder surfaces, its not a lube, more like an ash. Micro welding is stopped or slowed, because TEL cools the combustion temperature. Hot exhaust with scavengers prevent lead attachment to valve and seat contacts.

 

[2strokeNorthstar]

Valve seat lubrication...when it was phased out, valves recessed in their heads.

Yes, modern engines have hardened seats, so far less need.

First quad was in 1986. So all of them don’t need or desire lead. Get some race gas more suited to the intended use of the quad

 

[BusyLittleShop]

First quad was in 1986. So all of them don’t need or desire lead. Get some race gas more suited to the intended use of the quad

True... primary use of tetraethyl lead was knock or detonation control which engineers
had to solve with new combustion chambers because leaded pump fuel was being
phased out in the 60s...

Knocking is defined as an explosive combustion of part of the fuel/air
cylinder charge, after burning begins... What the ear hears are the
shock waves of the normal flame pattern colliding with the detonated
fuel/air mixture...

The rule is don't buy more octane than you need...

Our internal combustion engines speak in their own language as to
the correct octane... the ping or knock is their cry for the next
higher octane... no ping means engine satisfied... smart riders start
with the lowest octane and work up listening for a continuous ping or
knocking...

The story how lead got into our fuels started with high compression
aircraft engines back in 1921... a young engineer fresh out of college
named Charles Kettering started Dayton Engineering Labs Company or
Delco... he invented the first battery ignition systems for aircraft
engines... when protagonists in the field of aviation widely blamed
his battery ignition systems on knock or detonation Kettering
commanded his young assistant Thomas A. Midgley on a investigation of
detonation. motivated as much by a desire to protect Delco's
reputation as by scientific altruism. Midgley worked for months over
his single cylinder engine and famous "bouncing pin" which was devised
to measure differences in detonation pressures. and he soon determined
that detonation depended on both fuel grade and engine compression
ratio. Thinking at first that fuel color influenced knock. Midgley
added iodine to his fuel theorizing a dark-colored fuel would absorb
more heat energy and vaporize more quickly. When the knock diminished
he smelled success, but it did not come in the form . he suspected.
Further experiments forced him to discard the fuel color idea but led
in turn to a long. frustrating line of trial anti-knock additives. GM.
parent company of Delco. encouraged Midgley and his assistant T. A.
Boyd. who in a vigorous program, individually tested more than 30,000
compounds and their discouragement mounted with the list. On December
9, 1921. a chilly Friday. Midgley and Boyd were anticipating the
weekend's respite from their series of relentless, routine tests when
suddenly the engine was not behaving the same at all. Jolted into
disbelief, Midgley had quite literally stumbled onto the remarkable
antiknock properties of an obscure substance called tetraethyl lead.
This proved to be without doubt the greatest single discovery in the
development of aviation fuels; not only did this additive make higher
power possible. it enabled the aeroplane to fly farther on a given
amount of fuel- it gave the aeroplane range- and in turn enabled the
successful engines that dominated aviation until the advent of gas
turbines. In 1967 the remarkable Mr. Midgley was still active as
president of the American Chemical Society.

 

[2strokeNorthstar]

True... primary use of tetraethyl lead was knock or detonation control which engineers
had to solve with new combustion chambers because leaded pump fuel was being
phased out in the 60s...

Knocking is defined as an explosive combustion of part of the fuel/air
cylinder charge, after burning begins... What the ear hears are the
shock waves of the normal flame pattern colliding with the detonated
fuel/air mixture...

The rule is don't buy more octane than you need...

Our internal combustion engines speak in their own language as to
the correct octane... the ping or knock is their cry for the next
higher octane... no ping means engine satisfied... smart riders start
with the lowest octane and work up listening for a continuous ping or
knocking...

The story how lead got into our fuels started with high compression
aircraft engines back in 1921... a young engineer fresh out of college
named Charles Kettering started Dayton Engineering Labs Company or
Delco... he invented the first battery ignition systems for aircraft
engines... when protagonists in the field of aviation widely blamed
his battery ignition systems on knock or detonation Kettering
commanded his young assistant Thomas A. Midgley on a investigation of
detonation. motivated as much by a desire to protect Delco's
reputation as by scientific altruism. Midgley worked for months over
his single cylinder engine and famous "bouncing pin" which was devised
to measure differences in detonation pressures. and he soon determined
that detonation depended on both fuel grade and engine compression
ratio. Thinking at first that fuel color influenced knock. Midgley
added iodine to his fuel theorizing a dark-colored fuel would absorb
more heat energy and vaporize more quickly. When the knock diminished
he smelled success, but it did not come in the form . he suspected.
Further experiments forced him to discard the fuel color idea but led
in turn to a long. frustrating line of trial anti-knock additives. GM.
parent company of Delco. encouraged Midgley and his assistant T. A.
Boyd. who in a vigorous program, individually tested more than 30,000
compounds and their discouragement mounted with the list. On December
9, 1921. a chilly Friday. Midgley and Boyd were anticipating the
weekend's respite from their series of relentless, routine tests when
suddenly the engine was not behaving the same at all. Jolted into
disbelief, Midgley had quite literally stumbled onto the remarkable
antiknock properties of an obscure substance called tetraethyl lead.
This proved to be without doubt the greatest single discovery in the
development of aviation fuels; not only did this additive make higher
power possible. it enabled the aeroplane to fly farther on a given
amount of fuel- it gave the aeroplane range- and in turn enabled the
successful engines that dominated aviation until the advent of gas
turbines. In 1967 the remarkable Mr. Midgley was still active as
president of the American Chemical Society.

Cool history lesson. Never knew all that. Since I was a kid everything was unleaded. 100% correct on the only use the highest octane you need. Using higher you actually lose power. Despite the cool smell. I’ve built a few 2 cycle race motors and have had some experience with race gas. 100 octane is usually all most mildly modified motors need. It can be had for less than $10 a gallon

 

[BusyLittleShop]

Here is the rest of history how lead was legislated out of our fuels...

Clair Cameron Patterson could not isolate his rock samples from lead
contamination in the lab in an effort to determine the age of the
earth... he was shocked to learn lead was everywhere and developed the
first sealed clean lab to prevent lead from messing up the data...

The University of Chicago developed a new method for counting lead
isotopes in igneous rocks, and assigned it to Clair Cameron Patterson
as a dissertation project in 1948. During this period he operated
under the assumption that meteorites are left-over materials from the
creation of the Solar System, and thus by measuring the age of one of
these rocks the age of the Earth would be revealed. Gathering the
materials required time, and in 1953, Clair Cameron Patterson had his
final specimens from the Canyon Diablo meteorite. He took them to the
Argonne National Laboratory, where he was granted time on a late model
mass spectrometer.

In a meeting in Wisconsin soon afterward, Patterson revealed the
results of his study. The definitive age of the Earth is 4.550 billion
years (give or take 70 million years). This number still stands,
although the margin of error is now down to about 20 million years.

His ability to isolate microgram quantities of lead from ordinary
rocks and determine their isotope composition led him to examining the
lead in ocean sediment samples from the Atlantic and Pacific. Deriving
from the different ages at which the landmasses had drained into the
ocean, he was able to show that the amount of anthropogenic lead
presently dispersed into the environment was about eighty times the
amount being deposited in the ocean sediments: the geochemical cycle
for lead appeared to be badly out of balance.

The limitations of the analytic procedures led to him using other
approaches. He found that deep ocean water contained 3-10 times less
lead than surface water, in contrast to similar metals such as barium.
This led him to doubt the commonly held view that lead concentrations
had only grown by a factor of two over naturally occurring levels.

Patterson returned to the problem of his initial experiment and the
contamination he had found in the blanks used for sampling. He
determined through ice-core samples from Greenland that atmospheric
lead levels had begun to increase steadily and dangerously soon after
tetraethyl lead began to see widespread use in fuel, when it was
discovered to reduce engine knock in internal combustion engines.
Patterson subsequently identified this, along with the various other
uses of lead in manufacturing, as the cause of the contamination of
his samples, and because of the significant public-health implications
of his findings, he devoted the rest of his life to removing as much
introduced lead from the environment as possible.

Beginning in 1965, with the publication of Contaminated and Natural
Lead Environments of Man, Patterson tried to draw public attention to
the problem of increased lead levels in the environment and the food
chain due to lead from industrial sources. Perhaps partly because he
was criticizing the experimental methods of other scientists, he
encountered strong opposition from recognized experts such as Robert
A. Kehoe.

In his effort to ensure that lead was removed from gasoline
(petroleum), Patterson fought against the lobbying power of the Ethyl
Corporation (which employed Kehoe), against the legacy of Thomas
Midgley — which included tetraethyllead and chlorofluorocarbons — and
against the lead additive industry as a whole. Following Patterson's
criticism of the lead industry, he was refused contracts with many
research organizations, including the supposedly neutral United States
Public Health Service. In 1971 he was excluded from a National
Research Council (NRC) panel on atmospheric lead contamination, even
though he was the foremost expert on the subject at that time.[4]

Patterson's efforts ultimately led to the Environmental Protection
Agency announcing in 1973 a reduction of 60-65% in phased steps, and
ultimately the removal of lead from all standard, consumer, automotive
gasoline in the United States by 1986. Lead levels within the blood of
Americans are reported to have dropped by up to 80% by the late
1990s.[5]

He then turned his attention to lead in food where similar
experimental deficiencies had masked the increase. In one study he
showed an increase in lead levels from 0.3 to 1400 nanograms per gram
in certain canned fish compared with fresh, whilst the official
laboratory had reported an increase of 400 to 700.[6] He compared the
lead, barium and calcium levels in 1600 year-old Peruvian skeletons
and showed a 700- to 1200-fold increase in lead levels in modern human
bones with no comparable changes in the barium and calcium levels.[7]

In 1978 he was appointed to a NRC panel which accepted many of the
increases and the need for reductions but argued the need for more
research.[8] His opinions were expressed in a 78-page minority report
which argued that control measures should start immediately, including
gasoline, food containers, paint, glazes and water distribution
systems. Thirty years later, most of these have been accepted and
implemented in the United States and many other parts of the world.

 

[Exhaustgases]

TEL also well know as corrosive to valves, seats and other combustion space metals.
The goal was to reduce it to lower levels and still have an antidetonate back in the early 50's.
The remark about blood lead levels reduced, sure, lead replaced by radio isotopes, thanks to all that
"clean" energy.