COZY: Fuel Grade Requirements for Lycoming Engines


Izzy
 

None of those documents seem to address the questions of what will replace rhe function that lead provides for….

yes, octaine/compression is critical,  but if the lead was always optional, the  why have in the fuel? And if the lead was required, than what in the new fuels replaces that function? 

Seems like some important details are  being ignored for the safe of good policy. 



Izzy
(603)410-7277

On Jun 10, 2022, at 20:17, Marc J. Zeitlin <marc_zeitlin@...> wrote:


Folks:

During the discussion after my presentation at the Columbia Fly-In, the topic of Fuel grade requirements came up (I have no idea what tangent caused that, but whatever). Given the new 94UL, 100R, and other unleaded aviation fuels that either are or will soon be available, it behooves us to know what fuel we can use in our engines, as 100LL slowly starts to disappear (and good riddance, for many reasons). John Caulkins had a couple of good articles recently in the COBA (nee CSA) newsletter, discussing the issues around the new unleaded fuels, but he didn't discuss what could be used where. An article in this month's AOPA magazine does discuss it, but at a high level - not "you can use this if that".

At any rate, when I pull out my Lycoming O-360 operator's manual, in the "Fuel and Oil" section in Chapter 3, it lists what fuel is required depending upon your engine's model #. I have an O-360-A2A, so theoretically, even with a compression ratio of 8.5:1, I am limited to 100/100LL. HOWEVER, if I go to the Swift Fuel 94UL FAQ here:


and the Lycoming Service Instruction here:


both clearly indicate that my engine is approved to use Swift 94UL fuel in lieu of 100LL. When 100 octane unleaded fuels become available, one assumes that those would be acceptable as well, given the identical octane level.

So you should be able, if you know what engine you have, to easily determine whether available unleaded fuels are acceptable for use in your engine. And given our E-AB nature, we do not need STC's to do so.

All bets are off for 94UL, however, if you've installed high compression pistons in your engine - anything higher than the operator's manual compression ratio makes any approvals void, as it's the compression ratio and octane level that work together to eliminate the threat of detonation or pre-ignition. You'll have to wait for 100 octane unleaded fuel before switching. Just another reason not to screw with the compression ratio unless you're racing for $$$.

Hope this is useful.

--
Marc J. Zeitlin                      marc_zeitlin@...
                                            http://www.cozybuilders.org/
Copyright © 2022                     Burnside Aerospace

--
You received this message because you are subscribed to the Google Groups "COZY Builders Mailing List" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cozy_builders+unsubscribe@....
To view this discussion on the web visit https://groups.google.com/d/msgid/cozy_builders/CAMCASg7JEX9aTdDE_0R6L42scVYTv4OFTCyRQorD5MkNjGu2Mg%40mail.gmail.com.


Marc J. Zeitlin
 

Izzy Briggs wrote:

None of those documents seem to address the questions of what will replace rhe function that lead provides for….

The lead was there to increase octane #'s - nothing else. It was a cheap way of doing that. Some folks claimed that it also lubricated valves, but there is zero evidence for that, and as we see, it causes a lot of other functional problems in engines that will go away when the lead does (stuck valves, etc.).

yes, octaine/compression is critical,  but if the lead was always optional, the  why have in the fuel? And if the lead was required, than what in the new fuels replaces that function?

There are other octane boosters, most of which are more expensive than lead. The lead was not optional - it was just the cheapest way of getting octane levels up, as long as you don't care about poisoning air, water, animals, plants and people, which we didn't for a long time. The octane boosting replacement chemicals are far less noxious (although not without issues).

Seems like some important details are  being ignored for the safe of good policy. 

Nothing is being ignored. That's one of the reasons it's taken so long to get replacements that meet all the requirements for high compression and turbo-charged engines, which are the ones that use about 2/3 of all 100LL.

--
Marc J. Zeitlin                      marc_zeitlin@...
                                            http://www.cozybuilders.org/
Copyright © 2022                     Burnside Aerospace


Izzy
 

Evidence either way is elusive. Personally, I believe there is more evidence to support banning fast food, anti-freeze and vaping as an environment hazard, but alas they have staunch well funded defenders unlike avgas.

I’m just waiting for the first fatality to be reported because someone unknowingly put the lower octane stuff in their engines and broke the engine in flight.  

If aircraft engines were not so outrageously expensive to maintain, I might be more inclined to go along with the transition, but it still seems so trite, just another convenient way to suppress aviation activity. 

Izzy
(603)410-7277

On Jun 11, 2022, at 01:08, Marc J. Zeitlin <marc.j.zeitlin@...> wrote:


Izzy Briggs wrote:

None of those documents seem to address the questions of what will replace rhe function that lead provides for….

The lead was there to increase octane #'s - nothing else. It was a cheap way of doing that. Some folks claimed that it also lubricated valves, but there is zero evidence for that, and as we see, it causes a lot of other functional problems in engines that will go away when the lead does (stuck valves, etc.).

yes, octaine/compression is critical,  but if the lead was always optional, the  why have in the fuel? And if the lead was required, than what in the new fuels replaces that function?

There are other octane boosters, most of which are more expensive than lead. The lead was not optional - it was just the cheapest way of getting octane levels up, as long as you don't care about poisoning air, water, animals, plants and people, which we didn't for a long time. The octane boosting replacement chemicals are far less noxious (although not without issues).

Seems like some important details are  being ignored for the safe of good policy. 

Nothing is being ignored. That's one of the reasons it's taken so long to get replacements that meet all the requirements for high compression and turbo-charged engines, which are the ones that use about 2/3 of all 100LL.

--
Marc J. Zeitlin                      marc_zeitlin@...
                                            http://www.cozybuilders.org/
Copyright © 2022                     Burnside Aerospace


saccani@y7mail.com
 

Hardly zero evidence of lead bromides being significant in valve seat lubrication.  Take a gander at;

Godfrey, Douglas, and Richard L. Courtney. “Investigation of the Mechanism of Exhaust Valve Seat Wear in Engines Run on Unleaded Gasoline.” SAE Transactions, vol. 80, 1971, pp. 1449–54. 

That was the first paper to demonstrate and describe the mechanisms by which lead bromides reduced valve seat wear.  Reduced welding of valve to valve seat and so forth falls under tribology, but as it doesn’t involve fluid motion, it is not strictly lubrication, but most don’t make that distinction.  Still, the effects were significant and beneficial - which doesn’t negate the issue of valve sticking and so on.  As we know, there are detail changes to engine construction to improve durability with unleaded fuels, but there are also many old aero engines out there that have yet to incorporate these changes.

The next significant paper was;
Schoonveld, Gary A., Richard K. Riley, Stephen P. Thomas, and S. Schiff. “Exhaust Valve Recession with Low-Lead Gasolines.” SAE Transactions 95 (1986): 700–712. 

Which showed that reducing the lead content in leaded fuels led to a significant increase in valve seat recession and reduced engine durability.

 This paper from 2000 rounds up many factors relevant to the issues and demonstrated that other metallic additives could take the place of lead bromides in reducing exhaust valve seat recession;

Hutcheson, R., "Valve Seat Recession - An Independent Review of Existing Data," SAE Technical Paper 2000-01-2015, 2000,

Incidently, you missed out on the significant corrosion aspects of hydrobromic acid and aluminium bromide resulting from the use of bromide lead scavengers.  Lead bromide also directly attacks steel exhaust components.
 
Conversely, lead bromides also significantly *increased* valve seat recession on earlier engine designs were the valve seat was machined directly into cast iron heads rather than being an insert, mainly by corrosion.

Cheers,
Paul Saccani

On 11 Jun 2022, at 13:08, Marc J. Zeitlin <marc_zeitlin@...> wrote:


Izzy Briggs wrote:

None of those documents seem to address the questions of what will replace rhe function that lead provides for….

The lead was there to increase octane #'s - nothing else. It was a cheap way of doing that. Some folks claimed that it also lubricated valves, but there is zero evidence for that, and as we see, it causes a lot of other functional problems in engines that will go away when the lead does (stuck valves, etc.).

yes, octaine/compression is critical,  but if the lead was always optional, the  why have in the fuel? And if the lead was required, than what in the new fuels replaces that function?

There are other octane boosters, most of which are more expensive than lead. The lead was not optional - it was just the cheapest way of getting octane levels up, as long as you don't care about poisoning air, water, animals, plants and people, which we didn't for a long time. The octane boosting replacement chemicals are far less noxious (although not without issues).

Seems like some important details are  being ignored for the safe of good policy. 

Nothing is being ignored. That's one of the reasons it's taken so long to get replacements that meet all the requirements for high compression and turbo-charged engines, which are the ones that use about 2/3 of all 100LL.

--
Marc J. Zeitlin                      marc_zeitlin@...
                                            http://www.cozybuilders.org/
Copyright © 2022                     Burnside Aerospace

--
You received this message because you are subscribed to the Google Groups "COZY Builders Mailing List" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cozy_builders+unsubscribe@....
To view this discussion on the web visit https://groups.google.com/d/msgid/cozy_builders/CAMCASg5x3cXi2MXaS_q001dOr%2B%2BpHG%3DN%2BzQ1ERiAXpNG_TsObw%40mail.gmail.com.


Izzy
 

As metallurgy has improved since the 1920’s the valve/conditioning justifications may no longer be relevant. And perhaps it was bullshit back then too! 

Hard to trust corporate backed profit driven “science”.

Izzy
(603)410-7277

On Jun 11, 2022, at 11:20, Paul Saccani <saccani@...> wrote:

Hardly zero evidence of lead bromides being significant in valve seat lubrication.  Take a gander at;

Godfrey, Douglas, and Richard L. Courtney. “Investigation of the Mechanism of Exhaust Valve Seat Wear in Engines Run on Unleaded Gasoline.” SAE Transactions, vol. 80, 1971, pp. 1449–54. 

That was the first paper to demonstrate and describe the mechanisms by which lead bromides reduced valve seat wear.  Reduced welding of valve to valve seat and so forth falls under tribology, but as it doesn’t involve fluid motion, it is not strictly lubrication, but most don’t make that distinction.  Still, the effects were significant and beneficial - which doesn’t negate the issue of valve sticking and so on.  As we know, there are detail changes to engine construction to improve durability with unleaded fuels, but there are also many old aero engines out there that have yet to incorporate these changes.

The next significant paper was;
Schoonveld, Gary A., Richard K. Riley, Stephen P. Thomas, and S. Schiff. “Exhaust Valve Recession with Low-Lead Gasolines.” SAE Transactions 95 (1986): 700–712. 

Which showed that reducing the lead content in leaded fuels led to a significant increase in valve seat recession and reduced engine durability.

 This paper from 2000 rounds up many factors relevant to the issues and demonstrated that other metallic additives could take the place of lead bromides in reducing exhaust valve seat recession;

Hutcheson, R., "Valve Seat Recession - An Independent Review of Existing Data," SAE Technical Paper 2000-01-2015, 2000,

Incidently, you missed out on the significant corrosion aspects of hydrobromic acid and aluminium bromide resulting from the use of bromide lead scavengers.  Lead bromide also directly attacks steel exhaust components.
 
Conversely, lead bromides also significantly *increased* valve seat recession on earlier engine designs were the valve seat was machined directly into cast iron heads rather than being an insert, mainly by corrosion.

Cheers,
Paul Saccani

On 11 Jun 2022, at 13:08, Marc J. Zeitlin <marc_zeitlin@...> wrote:


Izzy Briggs wrote:

None of those documents seem to address the questions of what will replace rhe function that lead provides for….

The lead was there to increase octane #'s - nothing else. It was a cheap way of doing that. Some folks claimed that it also lubricated valves, but there is zero evidence for that, and as we see, it causes a lot of other functional problems in engines that will go away when the lead does (stuck valves, etc.).

yes, octaine/compression is critical,  but if the lead was always optional, the  why have in the fuel? And if the lead was required, than what in the new fuels replaces that function?

There are other octane boosters, most of which are more expensive than lead. The lead was not optional - it was just the cheapest way of getting octane levels up, as long as you don't care about poisoning air, water, animals, plants and people, which we didn't for a long time. The octane boosting replacement chemicals are far less noxious (although not without issues).

Seems like some important details are  being ignored for the safe of good policy. 

Nothing is being ignored. That's one of the reasons it's taken so long to get replacements that meet all the requirements for high compression and turbo-charged engines, which are the ones that use about 2/3 of all 100LL.

--
Marc J. Zeitlin                      marc_zeitlin@...
                                            http://www.cozybuilders.org/
Copyright © 2022                     Burnside Aerospace

--
You received this message because you are subscribed to the Google Groups "COZY Builders Mailing List" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cozy_builders+unsubscribe@....
To view this discussion on the web visit https://groups.google.com/d/msgid/cozy_builders/CAMCASg5x3cXi2MXaS_q001dOr%2B%2BpHG%3DN%2BzQ1ERiAXpNG_TsObw%40mail.gmail.com.

--
You received this message because you are subscribed to the Google Groups "COZY Builders Mailing List" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cozy_builders+unsubscribe@....
To view this discussion on the web visit https://groups.google.com/d/msgid/cozy_builders/02A5529C-3BFC-41EF-A8A1-433AFBA9CB39%40ii.net.


saccani@y7mail.com
 

Hard to trust reasoning that is completely wrong headed.  I noted that TEL *damaged* 1920’s  metallurgy (as still made into the late forties), whilst two of the papers cited dealt with engines in large volume production that were only made between 1961 and 2002, and the other paper focused on 1995-2002.  So you raise fictional issues, whilst mistaking an issue relevant to 1920’s engines being *damaged* by leaded fuel as somehow being “corporate science” as you describe it.  As it happened, that was research sponsored by the Civil Aeronautics Board.

I am disappointed by the amount of thought you put into this. 

There are significant numbers of aero engines still using first run cylinders made before 1970, significant changes have quietly been made to the seats used in aero engine cylinders made since 1978, better suiting them to low lead and even unleaded fuels.

Corrosion from hydrobromic acid and aluminium bromide remains a significant issue today, even with low lead fuel, because steel barrels are still being used with engines having aluminium alloy heads and cases.  But with less lead, there is of course less of it, and you don’t get it at all with unleaded fuel.

Cheers,
Paul Saccani

On 12 Jun 2022, at 02:35, 'Izzy Briggs' via COZY Builders Mailing List <cozy_builders@...> wrote:

As metallurgy has improved since the 1920’s the valve/conditioning justifications may no longer be relevant. And perhaps it was bullshit back then too! 

Hard to trust corporate backed profit driven “science”.

Izzy
(603)410-7277

On Jun 11, 2022, at 11:20, Paul Saccani <saccani@...> wrote:

Hardly zero evidence of lead bromides being significant in valve seat lubrication.  Take a gander at;

Godfrey, Douglas, and Richard L. Courtney. “Investigation of the Mechanism of Exhaust Valve Seat Wear in Engines Run on Unleaded Gasoline.” SAE Transactions, vol. 80, 1971, pp. 1449–54. 

That was the first paper to demonstrate and describe the mechanisms by which lead bromides reduced valve seat wear.  Reduced welding of valve to valve seat and so forth falls under tribology, but as it doesn’t involve fluid motion, it is not strictly lubrication, but most don’t make that distinction.  Still, the effects were significant and beneficial - which doesn’t negate the issue of valve sticking and so on.  As we know, there are detail changes to engine construction to improve durability with unleaded fuels, but there are also many old aero engines out there that have yet to incorporate these changes.

The next significant paper was;
Schoonveld, Gary A., Richard K. Riley, Stephen P. Thomas, and S. Schiff. “Exhaust Valve Recession with Low-Lead Gasolines.” SAE Transactions 95 (1986): 700–712. 

Which showed that reducing the lead content in leaded fuels led to a significant increase in valve seat recession and reduced engine durability.

 This paper from 2000 rounds up many factors relevant to the issues and demonstrated that other metallic additives could take the place of lead bromides in reducing exhaust valve seat recession;

Hutcheson, R., "Valve Seat Recession - An Independent Review of Existing Data," SAE Technical Paper 2000-01-2015, 2000,

Incidently, you missed out on the significant corrosion aspects of hydrobromic acid and aluminium bromide resulting from the use of bromide lead scavengers.  Lead bromide also directly attacks steel exhaust components.
 
Conversely, lead bromides also significantly *increased* valve seat recession on earlier engine designs were the valve seat was machined directly into cast iron heads rather than being an insert, mainly by corrosion.

Cheers,
Paul Saccani

On 11 Jun 2022, at 13:08, Marc J. Zeitlin <marc_zeitlin@...> wrote:


Izzy Briggs wrote:

None of those documents seem to address the questions of what will replace rhe function that lead provides for….

The lead was there to increase octane #'s - nothing else. It was a cheap way of doing that. Some folks claimed that it also lubricated valves, but there is zero evidence for that, and as we see, it causes a lot of other functional problems in engines that will go away when the lead does (stuck valves, etc.).

yes, octaine/compression is critical,  but if the lead was always optional, the  why have in the fuel? And if the lead was required, than what in the new fuels replaces that function?

There are other octane boosters, most of which are more expensive than lead. The lead was not optional - it was just the cheapest way of getting octane levels up, as long as you don't care about poisoning air, water, animals, plants and people, which we didn't for a long time. The octane boosting replacement chemicals are far less noxious (although not without issues).

Seems like some important details are  being ignored for the safe of good policy. 

Nothing is being ignored. That's one of the reasons it's taken so long to get replacements that meet all the requirements for high compression and turbo-charged engines, which are the ones that use about 2/3 of all 100LL.

--
Marc J. Zeitlin                      marc_zeitlin@...
                                            http://www.cozybuilders.org/
Copyright © 2022                     Burnside Aerospace

--
You received this message because you are subscribed to the Google Groups "COZY Builders Mailing List" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cozy_builders+unsubscribe@....
To view this discussion on the web visit https://groups.google.com/d/msgid/cozy_builders/CAMCASg5x3cXi2MXaS_q001dOr%2B%2BpHG%3DN%2BzQ1ERiAXpNG_TsObw%40mail.gmail.com.

--
You received this message because you are subscribed to the Google Groups "COZY Builders Mailing List" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cozy_builders+unsubscribe@....
To view this discussion on the web visit https://groups.google.com/d/msgid/cozy_builders/02A5529C-3BFC-41EF-A8A1-433AFBA9CB39%40ii.net.

--
You received this message because you are subscribed to the Google Groups "COZY Builders Mailing List" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cozy_builders+unsubscribe@....
To view this discussion on the web visit https://groups.google.com/d/msgid/cozy_builders/657921EE-B044-41C9-97E3-A96249B9ADA2%40yahoo.com.


Marc J. Zeitlin
 

Paul Saccani wrote:

Hardly zero evidence of lead bromides being significant in valve seat lubrication...

I am currently in Iceland and do not have my July AOPA magazine in front of me, but I would suggest looking at it as there was an article that discussed the belief that lead was a lubricant for valve seats, and the newer (newer than the articles you cite) information that discusses what the actual issues were with valve seat recession.

I am not an engine expert nor a gasoline expert, but they seemed pretty clear that it wasn't the lead that was preventing valve seat recession.

In any case, not having lead will be better all around (maybe not in EVERY case, but most certainly on the average and for ALMOST all aircraft engines) than having it.

--
Marc J. Zeitlin                      marc_zeitlin@...
                                            http://www.cozybuilders.org/
Copyright © 2022                     Burnside Aerospace


Mike Tooze
 

This is all rather academic and I don't like the concept of discarding papers merely because of their age.

As a Canardian I am more concerned as to the affect of these 'new' fuels on my aircraft and its systems. Particularly for those, unlike me, who chose to use other than Safety Pox for the structure of their fuel tanks. (My tanks have only ever 'seen' 80/82 or these days, 100LL - and I plan to stay that way.)


As a side issue, as Marc makes the environmental point. It was after the introduction of non-leaded motor fuels (coincidence?) that I noticed a marked reduction in the density of insect strikes on my Eze, such as not always having to wash it down after a flight. Whereas in the old days I could never hangar back home without a thorough wash-down. The rough dating eludes me but I was so concerned about this I made a post to [c-a] on this topic at that time. But there was no interest - how things have changed!


Mike T

O-235 VE




------ Original Message ------
From: "saccani@..." <saccani@...>
To: "Izzy Briggs" <inbriggs@...>
Cc: "Marc J. Zeitlin" <marc_zeitlin@...>; "Canard Aviators" <canard-aviators@canardzone.groups.io>; "COZY Builders" <cozy_builders@...>
Sent: Saturday, 11 Jun, 22 At 22:33
Subject: Re: [c-a] COZY: Fuel Grade Requirements for Lycoming Engines

Hard to trust reasoning that is completely wrong headed. I noted that TEL *damaged* 1920’s metallurgy (as still made into the late forties), whilst two of the papers cited dealt with engines in large volume production that were only made between 1961 and 2002, and the other paper focused on 1995-2002. So you raise fictional issues, whilst mistaking an issue relevant to 1920’s engines being *damaged* by leaded fuel as somehow being “corporate science” as you describe it. As it happened, that was research sponsored by the Civil Aeronautics Board.

I am disappointed by the amount of thought you put into this.

There are significant numbers of aero engines still using first run cylinders made before 1970, significant changes have quietly been made to the seats used in aero engine cylinders made since 1978, better suiting them to low lead and even unleaded fuels.

Corrosion from hydrobromic acid and aluminium bromide remains a significant issue today, even with low lead fuel, because steel barrels are still being used with engines having aluminium alloy heads and cases. But with less lead, there is of course less of it, and you don’t get it at all with unleaded fuel.

Cheers,
Paul Saccani

On 12 Jun 2022, at 02:35, 'Izzy Briggs' via COZY Builders Mailing List <cozy_builders@...> wrote:

As metallurgy has improved since the 1920’s the valve/conditioning justifications may no longer be relevant. And perhaps it was bullshit back then too!

Hard to trust corporate backed profit driven “science”.

Izzy
(603)410-7277

On Jun 11, 2022, at 11:20, Paul Saccani <saccani@...> wrote:

Hardly zero evidence of lead bromides being significant in valve seat lubrication. Take a gander at;

Godfrey, Douglas, and Richard L. Courtney. “Investigation of the Mechanism of Exhaust Valve Seat Wear in Engines Run on Unleaded Gasoline.” SAE Transactions, vol. 80, 1971, pp. 1449–54.

That was the first paper to demonstrate and describe the mechanisms by which lead bromides reduced valve seat wear. Reduced welding of valve to valve seat and so forth falls under tribology, but as it doesn’t involve fluid motion, it is not strictly lubrication, but most don’t make that distinction. Still, the effects were significant and beneficial - which doesn’t negate the issue of valve sticking and so on. As we know, there are detail changes to engine construction to improve durability with unleaded fuels, but there are also many old aero engines out there that have yet to incorporate these changes.

The next significant paper was;
Schoonveld, Gary A., Richard K. Riley, Stephen P. Thomas, and S. Schiff. “Exhaust Valve Recession with Low-Lead Gasolines.” SAE Transactions 95 (1986): 700–712.

Which showed that reducing the lead content in leaded fuels led to a significant increase in valve seat recession and reduced engine durability.

This paper from 2000 rounds up many factors relevant to the issues and demonstrated that other metallic additives could take the place of lead bromides in reducing exhaust valve seat recession;

Hutcheson, R., "Valve Seat Recession - An Independent Review of Existing Data," SAE Technical Paper 2000-01-2015, 2000,

Incidently, you missed out on the significant corrosion aspects of hydrobromic acid and aluminium bromide resulting from the use of bromide lead scavengers. Lead bromide also directly attacks steel exhaust components.
Conversely, lead bromides also significantly *increased* valve seat recession on earlier engine designs were the valve seat was machined directly into cast iron heads rather than being an insert, mainly by corrosion.

Cheers,
Paul Saccani

On 11 Jun 2022, at 13:08, Marc J. Zeitlin <marc_zeitlin@...> wrote:


Izzy Briggs wrote:

None of those documents seem to address the questions of what will replace rhe function that lead provides for….

The lead was there to increase octane #'s - nothing else. It was a cheap way of doing that. Some folks claimed that it also lubricated valves, but there is zero evidence for that, and as we see, it causes a lot of other functional problems in engines that will go away when the lead does (stuck valves, etc.).

yes, octaine/compression is critical, but if the lead was always optional, the why have in the fuel? And if the lead was required, than what in the new fuels replaces that function?

There are other octane boosters, most of which are more expensive than lead. The lead was not optional - it was just the cheapest way of getting octane levels up, as long as you don't care about poisoning air, water, animals, plants and people, which we didn't for a long time. The octane boosting replacement chemicals are far less noxious (although not without issues).

Seems like some important details are being ignored for the safe of good policy.

Nothing is being ignored. That's one of the reasons it's taken so long to get replacements that meet all the requirements for high compression and turbo-charged engines, which are the ones that use about 2/3 of all 100LL.

--

--
You received this message because you are subscribed to the Google Groups "COZY Builders Mailing List" group.
To unsubscribe from this group and stop receiving emails from it, send an email to unsubscribe@...">cozy_builders+unsubscribe@....
To view this discussion on the web visit https://groups.google.com/d/msgid/cozy_builders/CAMCASg5x3cXi2MXaS_q001dOr%2B%2BpHG%3DN%2BzQ1ERiAXpNG_TsObw%40mail.gmail.com.

--
You received this message because you are subscribed to the Google Groups "COZY Builders Mailing List" group.
To unsubscribe from this group and stop receiving emails from it, send an email to unsubscribe@...">cozy_builders+unsubscribe@....
To view this discussion on the web visit https://groups.google.com/d/msgid/cozy_builders/02A5529C-3BFC-41EF-A8A1-433AFBA9CB39%40ii.net.

--
You received this message because you are subscribed to the Google Groups "COZY Builders Mailing List" group.
To unsubscribe from this group and stop receiving emails from it, send an email to unsubscribe@...">cozy_builders+unsubscribe@....
To view this discussion on the web visit https://groups.google.com/d/msgid/cozy_builders/657921EE-B044-41C9-97E3-A96249B9ADA2%40yahoo.com.