Leaded/Unleaded gas history and engine info
February 14th, 2011, 12:27 PM
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Leaded/Unleaded gas history and engine info
I ran across a comment on a blog that I found very interesting; someone who was an active member of the EPA team doing research into effects of lead in gas, and part of her job was looking into how lack of lead would affect valve seats on older engines. I've seen various discussions of whether or not lead additives are needed, or hardened seats, etc, and thought it was worth passing on. Here's her comment (rather long, but worth reading):
The paper she refers to can be found here: http://www.sae.org/servlets/product;WebLogicSession=Lq1cptv135rkQrwJwT22zVcFyG yNHMl1K101jWGJcbhLGZXt76JG!487327552?PROD_TYP=PAPE R&PARENT_BPA_CD=GV&TECH_CD=FUELS
Search for 860090, and you will find a link to the pdf for the paper. Or, here's a direct download link for the pdf: http://www.sae.org/servlets/productD...PROD_CD=860090
I was involved in the EPA studies that resulted in the phase-out and eventual banning of leaded gasoline. At that time, the lead industry had a major disinformation campaign underway claiming that valve seats on older engines would be damaged by using unleaded gasoline. It was my job to look into that and other effects. SAE Paper No. 860090 is a review of the good and (mostly) bad effects of lead on vehicles.
My review showed that when engines were operated at high load for long periods, the oxide on the valve seat could wear away, allowing the valve to micro-weld to the seat when it banged down, and then jerking loose microscopic pieces of the seat when it pushed back up. Once it started, this "valve seat recession" would destroy the cylinder head in short order. Lead deposits on the valve seat acted like flour on a pastry board, keeping the valve from sticking. So far, that's what the industry had been claiming.
However, my review further documented that this was ONLY a problem if you ran the engine continuously at high speed and load for a long time -- that is, in formula 1 racing or dynamometer testing, but not in typical automotive service. In fact, I was able to show that quite a few organizations (including the U.S. Army!) had already shifted all of their older vehicles to unleaded gasoline, as it was too much trouble to provide both leaded fuel for the old and unleaded fuel for the newer vehicles.
My review ALSO showed that lead oxide deposits formed on spark plugs, corroding them and shorting them out, and on exhaust valve seats. Channels formed in the deposits would allow exhaust gas to leak out during combustion, damaging the valve. To combat these deposits, chlorine and bromine compounds were used in addition to TEL, in a mixture called "motor mix". The chlorine and bromine helped scavenge the lead deposits, but also formed acids in the oil (reducing oil life), and corroded exhaust pipes. Overall, the engine and vehicle damage due to the lead additives was much more important than the valve seat recession issue.
While I was looking into the engine issues, an EPA staffer named Joel Schwarz (now a fomer McArthur fellow at Harvard School of Public Health) was doing epidemiologic studies of lead impacts on health. He found that it was MUCH worse than previously thought, at blood lead levels that had previously been considered safe. The main impacts were mental retardation, deafness, and other neurological problems in children, and high blood pressure in adults -- leading to stroke and heart attacks.
When the Reagan administration came into office, they trumpeted their plans to apply cost-benefit analysis to environmental regulations, and Anne Gorsuch gave a speech to a small refiner's conference where she said that the lead regulations were on their way out. Then Joel Schwarz and an EPA economist named Hugh Pitcher, published their report showing that the benefits of eliminating lead in gasoline were more than ten times the costs, and the evil bitch was hoist with her own petard. EPA wound up adopting regulations that dropped the lead content down to 0.1 gram per gallon very quickly, then eliminated it entirely ten years later.
Average blood lead levels in the U.S. and other countries have come down dramatically with the elimination of leaded gasoline. A large part of the drop in heart attacks since the '70s is now thought to be due to lower blood lead concentrations.
Since the work in the U.S., I've been able to contribute to government decisions to phase out lead in five other countries: Thailand, Peru, Costa Rica, Mexico, and Sri Lanka, and I wrote a report for USAID on why and how countries should ban lead in their gasoline. The arguments in each case were the same -- "but the lead companies tell us that the unleaded gas will damage the older engines!" In none of these cases was there actually any widespread engine damage due to unleaded fuel.
My review showed that when engines were operated at high load for long periods, the oxide on the valve seat could wear away, allowing the valve to micro-weld to the seat when it banged down, and then jerking loose microscopic pieces of the seat when it pushed back up. Once it started, this "valve seat recession" would destroy the cylinder head in short order. Lead deposits on the valve seat acted like flour on a pastry board, keeping the valve from sticking. So far, that's what the industry had been claiming.
However, my review further documented that this was ONLY a problem if you ran the engine continuously at high speed and load for a long time -- that is, in formula 1 racing or dynamometer testing, but not in typical automotive service. In fact, I was able to show that quite a few organizations (including the U.S. Army!) had already shifted all of their older vehicles to unleaded gasoline, as it was too much trouble to provide both leaded fuel for the old and unleaded fuel for the newer vehicles.
My review ALSO showed that lead oxide deposits formed on spark plugs, corroding them and shorting them out, and on exhaust valve seats. Channels formed in the deposits would allow exhaust gas to leak out during combustion, damaging the valve. To combat these deposits, chlorine and bromine compounds were used in addition to TEL, in a mixture called "motor mix". The chlorine and bromine helped scavenge the lead deposits, but also formed acids in the oil (reducing oil life), and corroded exhaust pipes. Overall, the engine and vehicle damage due to the lead additives was much more important than the valve seat recession issue.
While I was looking into the engine issues, an EPA staffer named Joel Schwarz (now a fomer McArthur fellow at Harvard School of Public Health) was doing epidemiologic studies of lead impacts on health. He found that it was MUCH worse than previously thought, at blood lead levels that had previously been considered safe. The main impacts were mental retardation, deafness, and other neurological problems in children, and high blood pressure in adults -- leading to stroke and heart attacks.
When the Reagan administration came into office, they trumpeted their plans to apply cost-benefit analysis to environmental regulations, and Anne Gorsuch gave a speech to a small refiner's conference where she said that the lead regulations were on their way out. Then Joel Schwarz and an EPA economist named Hugh Pitcher, published their report showing that the benefits of eliminating lead in gasoline were more than ten times the costs, and the evil bitch was hoist with her own petard. EPA wound up adopting regulations that dropped the lead content down to 0.1 gram per gallon very quickly, then eliminated it entirely ten years later.
Average blood lead levels in the U.S. and other countries have come down dramatically with the elimination of leaded gasoline. A large part of the drop in heart attacks since the '70s is now thought to be due to lower blood lead concentrations.
Since the work in the U.S., I've been able to contribute to government decisions to phase out lead in five other countries: Thailand, Peru, Costa Rica, Mexico, and Sri Lanka, and I wrote a report for USAID on why and how countries should ban lead in their gasoline. The arguments in each case were the same -- "but the lead companies tell us that the unleaded gas will damage the older engines!" In none of these cases was there actually any widespread engine damage due to unleaded fuel.
Search for 860090, and you will find a link to the pdf for the paper. Or, here's a direct download link for the pdf: http://www.sae.org/servlets/productD...PROD_CD=860090
February 14th, 2011, 12:38 PM
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I'm not surprised by this at all. Wasn't AMOCO gas unleaded? I used it almost exclusively back in the day and never had issues with it. This was on a plain Jane set of 'E' heads with no inserts.
Now if they could just up the octane...............
Now if they could just up the octane...............
February 14th, 2011, 03:14 PM
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February 14th, 2011, 03:49 PM
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Amoco stations had "white gas", it was gasoline with nothing added like lead and whatever else they put in it far as I know.
People used it for their lawnmowers, maybe for boat motors too? It seems like everybody had a can that said "white gas" on the sides in their garage.
If you ever look at the gore on the side of a freeway off ramp when you're sitting in your car waiting for the light to change you'll see a ton of lead wheel weights sitting around.
The birds eat them and introduce the lead into the food chain, they get so heavy they have to walk everywhere too.
I see the little beggars standing there eating wheel weights and trying to thumb rides on the on ramp.
February 15th, 2011, 12:12 AM
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February 20th, 2011, 12:41 PM
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BS, what is your data base for that ridiculous assertion? Those EPA research papers were all controlled, double blind, randomized studies published in peer-reviewed science journals by named scientists with advanced degrees from highly respected academic institutions, I know them, I have my advanced degrees in Bio-Chemisty. Know your facts before putting such absurd drivel on here. Sorry, but EPA's results are correct.
Last edited by holidaysedan; February 20th, 2011 at 12:48 PM.
February 20th, 2011, 01:14 PM
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EPA is a nastly stuck up controlling SOB organization. They sleep withh people like Al Gore,Nancy Palosi and other tree hugging POS. If the EPA including current and past employees of the EPA along with the followers had thier way all classic cars and associated vehicles would be in the junk yard..The EPA is a runaway train and no one is willing to haul them in. If lead wasn't needed on older cars then why did they allow ALL military, federal and states to continue to use leaded fuel longer then the average joe.
I worked for a fleet repair company in New York and for three years after the ban we were still pumping leaded fuel for police fire and Goverment autos. Why?? They knew the damge that unleaded fuel did to the engines.
I worked for a fleet repair company in New York and for three years after the ban we were still pumping leaded fuel for police fire and Goverment autos. Why?? They knew the damge that unleaded fuel did to the engines.
February 20th, 2011, 01:41 PM
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You know, I didn't actually mean for this to become such a politicized topic.
It's just that there has been so much discussion as to whether or not hardened seats are needed for unleaded gas that I thought it would be interesting to see a researched, peer-reviewed, scientific report that essentially says no, hardened seats are not needed, and that the health detriments caused from using leaded gas are so severe that it's pretty much a no-brainer to use unleaded.
It's just that there has been so much discussion as to whether or not hardened seats are needed for unleaded gas that I thought it would be interesting to see a researched, peer-reviewed, scientific report that essentially says no, hardened seats are not needed, and that the health detriments caused from using leaded gas are so severe that it's pretty much a no-brainer to use unleaded.
February 20th, 2011, 02:22 PM
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Unfortunately, our country has gotten to a point where a significant portion of the population (majority? minority? I don't know.), both left and right, has lost essentially all faith / trust in the US government. I will admit that when I read that information, I was inclined to believe it, both because it was consistent with my own experience, and because it appeared in the SAE journal, but I took it with a grain of salt because of its connection to the government.
Perhaps if most of us hadn't spent our lives discovering different ways in which the government had been found to be lying to us ("LSD damages chromosomes," "The North Vietnamese attacked our Navy in International waters," "If Vietnam falls, the Reds will be headed for California," "We're not selling drugs to get weapons to sell to Iran and to finance the Contras, in direct violation of the law," "You'll get AIDS if you have sex without a condom," "Saddam's got weapons of mass destruction," etc., etc., etc.), we'd be more trusting, but, as my grandmother used to say,
"Fool me once, shame on you, fool me twice, shame on me."
A lot of Americans no longer see our government as being "of the people" or "for the people" and that's a very sad thing.
- Eric
Perhaps if most of us hadn't spent our lives discovering different ways in which the government had been found to be lying to us ("LSD damages chromosomes," "The North Vietnamese attacked our Navy in International waters," "If Vietnam falls, the Reds will be headed for California," "We're not selling drugs to get weapons to sell to Iran and to finance the Contras, in direct violation of the law," "You'll get AIDS if you have sex without a condom," "Saddam's got weapons of mass destruction," etc., etc., etc.), we'd be more trusting, but, as my grandmother used to say,
"Fool me once, shame on you, fool me twice, shame on me."
A lot of Americans no longer see our government as being "of the people" or "for the people" and that's a very sad thing.
- Eric
February 20th, 2011, 04:14 PM
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I understand what you are saying, but the fact remains: scientific peer-reviewed research is in a class by itself. Anyone can point at any single paper to "prove" their position; peer review establishes worldwide scientific credibility.
Is a paper credible? Has its purported claims been tested independently? Does the author of a paper have a particular agenda that causes him to slant the results? Look at what the overall body of scientists, who are overwhelmingly conservative in their judgements (they have to be; overreaching claims invalidate any usefulness to their research), are willing to state about any science research in order to judge the validity of a paper. That's what peer review is for.
If a paper has withstood lengthy peer review, it doesn't matter who commissioned it. In the short term, yes, it can make a difference; anyone remember the tobacco company "research" on the health effects of cigarettes? Or the "research" on vaccinations causing autism?
As an update, I just used the link i had originally posted, and it leads to a page that is charging for the full paper, which is very odd. When I first found it, I just downloaded the full pdf without seeing any charges. It's on my computer at work, I think, and I'll post some snippets of it.
The most interesting part I found had to do with how lead helped to reduce valve seat wear, and how the phenomenon is only an issue at extremes (i.e. sustained high rpm, heavy load use) such as long-term dyno testing and the like.
Is a paper credible? Has its purported claims been tested independently? Does the author of a paper have a particular agenda that causes him to slant the results? Look at what the overall body of scientists, who are overwhelmingly conservative in their judgements (they have to be; overreaching claims invalidate any usefulness to their research), are willing to state about any science research in order to judge the validity of a paper. That's what peer review is for.
If a paper has withstood lengthy peer review, it doesn't matter who commissioned it. In the short term, yes, it can make a difference; anyone remember the tobacco company "research" on the health effects of cigarettes? Or the "research" on vaccinations causing autism?
As an update, I just used the link i had originally posted, and it leads to a page that is charging for the full paper, which is very odd. When I first found it, I just downloaded the full pdf without seeing any charges. It's on my computer at work, I think, and I'll post some snippets of it.
The most interesting part I found had to do with how lead helped to reduce valve seat wear, and how the phenomenon is only an issue at extremes (i.e. sustained high rpm, heavy load use) such as long-term dyno testing and the like.
February 20th, 2011, 04:28 PM
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I understand and agree that information published in peer-reviewed journals is usually reasonably credible, provided you read the article carefully and review how the authors used statistics. In this case, as you noted, I was unable to read the whole paper because I was disinclined to pay for it. I'd love to be able to read it, though [hint].
And don't forget that Andrew Wakefield's now entirely discredited study on autism and the MMR vaccine was published in the exceptionally well-respected peer-reviewed journal The Lancet in 1998, and caused a tremendous amount of pain and suffering before being retracted by that same journal this past year.
- Eric
And don't forget that Andrew Wakefield's now entirely discredited study on autism and the MMR vaccine was published in the exceptionally well-respected peer-reviewed journal The Lancet in 1998, and caused a tremendous amount of pain and suffering before being retracted by that same journal this past year.
- Eric
February 20th, 2011, 04:58 PM
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Keeping lead out of the air is always a good thing. Never will I fight clean air. But I have seen too many minor small goverment agencies explode to be bloated and out of control
The EPA is a perfect example.
I have read many independent reports on the effects of unleaded fuel on older cars. Bottom line... is it is better for our health without it but our old classics do suffer. But we classic car owners can and will find a way around it. That is what makes our hobbies so much fun.
Now about getting AIDS from a toilet seat. THAT I BELIEVE!!!
The EPA is a perfect example.
I have read many independent reports on the effects of unleaded fuel on older cars. Bottom line... is it is better for our health without it but our old classics do suffer. But we classic car owners can and will find a way around it. That is what makes our hobbies so much fun.
Now about getting AIDS from a toilet seat. THAT I BELIEVE!!!
February 20th, 2011, 07:27 PM
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And don't forget that Andrew Wakefield's now entirely discredited study on autism and the MMR vaccine was published in the exceptionally well-respected peer-reviewed journal The Lancet in 1998, and caused a tremendous amount of pain and suffering before being retracted by that same journal this past year.
It also validates the other point I was making, that scientists as a body are conservative with their claims. It took years before scientists as a group were willing to state flatly that Wakefield's claims were simply wrong, not to mention deliberately fraudulent. Many were willing to go on record as expressing skepticism, however.
February 20th, 2011, 07:49 PM
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I suppose my point would be exactly that - that a person, never mind an entire profession, should never change direction radically just because some study tells them to.
In this case, I would be inclined to go with the findings of this paper, as it has not, to my knowledge been contradicted by later developments, but I am not an engineer, nor a member of the SAE, so there may be later findings I am unaware of.
- Eric
February 20th, 2011, 09:01 PM
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Some but not all EPA funded research is well done. Some but not all of the researchers are well qualified. My Ph.D. is in Chemistry and I worked with EPA researchers for years. Some deserve a lot of respect. I don't know how well done the lead studies were done, but there was a lot of political pressure to justify getting rid of lead, just as there was for DDT.
February 20th, 2011, 09:37 PM
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Certainly an interesting discussion here, wasn't the EPA founded in 1970 during the Nixon administration? I for one was surprised by that, considering the environment isn't usually the strongest plank in the Republican platform.
February 21st, 2011, 07:28 AM
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On the question about Amoco premium in the '50's, my dad was a refinery engineer at Amoco's Texas City refinery back then. Amoco marketed their unleaded premium gas as superior to leaded gas because lead had detrimental effects on IC engines. He personally never put much stock in that claim and I saw him many times fill up using half a tank of unleaded premium and half a tank of leaded regular. Sort of did his own blending to find the combo that wouldn't knock.
Last edited by weasel; February 21st, 2011 at 07:29 AM. Reason: mistake
February 21st, 2011, 08:49 AM
#23
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Politics have shifted massively over the past 50 years or so.
Remember that Republican Eisenhower warned us of the "military-industrial complex," Democrat Kennedy presided over the largest tax cuts before Reagan, Democrat Johnson started the open escalation of the Vietnam War, and Republican Nixon was first elected, among other things, because of his promise to get us out of Vietnam.
- Eric
March 6th, 2011, 11:26 PM
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Scientific theory should stand up to (and indeed welcome) the strongest scrutiny and if found at fault be revised as research advances knowledge of the subject.
As a result of such research we no longer have lead in gasoline, the lead soldiers my father had as toys are outlawed, modern medicine keeps us relatively disease free and we can exchange ideas and information on forums like this one.
Science becomes disreputable when vested interests publicise only what they want us to hear and suppresses what they prefer us not to know, the tobacco industry comes to mind as an example.
Human nature being what it is nobody likes their work to be discredited, but a good researcher should accept that they got it wrong if new research reveals flaws or errors.
I understand unleaded gas cost more than leaded because other octane boosters are more expensive, the oil companies didn't like it nor did the public think much of higher pump prices. Yet lead in gas was eventually phased out. The harmful effects of lead were well known but hidden from us for years but we no longer breathe lead fumes and cars are far more fuel efficient than they were.
I think independent research into possibly harmful products or practices is vital for the general good of the public. Of course it has to be paid for but I am willing to accept part of my tax burden going towards keeping check on profit driven businesses. I know the American way is all about doing business to make a profit but it should also have an obligation to act responsibly.
As a result of such research we no longer have lead in gasoline, the lead soldiers my father had as toys are outlawed, modern medicine keeps us relatively disease free and we can exchange ideas and information on forums like this one.
Science becomes disreputable when vested interests publicise only what they want us to hear and suppresses what they prefer us not to know, the tobacco industry comes to mind as an example.
Human nature being what it is nobody likes their work to be discredited, but a good researcher should accept that they got it wrong if new research reveals flaws or errors.
I understand unleaded gas cost more than leaded because other octane boosters are more expensive, the oil companies didn't like it nor did the public think much of higher pump prices. Yet lead in gas was eventually phased out. The harmful effects of lead were well known but hidden from us for years but we no longer breathe lead fumes and cars are far more fuel efficient than they were.
I think independent research into possibly harmful products or practices is vital for the general good of the public. Of course it has to be paid for but I am willing to accept part of my tax burden going towards keeping check on profit driven businesses. I know the American way is all about doing business to make a profit but it should also have an obligation to act responsibly.
May 27th, 2011, 04:15 PM
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I don't believe that lead had any anti-knock properties though I am not certain. What I am certain of is that in 1974 I owned a 1969 Pontiac LeMans and for the 2 or 3 times I tried to fill it up with Amoco unleaded back then it would knock.
May 27th, 2011, 04:23 PM
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Yes, tetraethyl lead (or "Ethyl") was the antiknock ingredient that enabled the development of modern automotive engines, and allowed compression ratios to rise above about 6:1.
They use others now, but Ethyl was the original in mass production.
- Eric
They use others now, but Ethyl was the original in mass production.
- Eric
May 27th, 2011, 04:39 PM
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So that begs the question why did Amoco make that kind of fuel back then if it would cause problems in most of the cars of the era?
I know I did buy the "white" Amoco fuel for my Coleman latern when I was in Boy Scouts, but there couldn't have been much of market just for Coleman laterns.
I know I did buy the "white" Amoco fuel for my Coleman latern when I was in Boy Scouts, but there couldn't have been much of market just for Coleman laterns.
May 27th, 2011, 05:16 PM
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I don't know about the Amoco fuel additives, but I'd guess they used something other than lead to reduce knock. Maybe one of the compounds used now?
If I recall, gasoline used to be pink, which I assume was because of the lead additive.
Now it seems to be yellow.
"White gas" can still be purchased as "Coleman fuel" in gallon containers at hardware stores.
As far as I know, white gas is essentially old-time gas from before they started adding additives (the sort of stuff your great-grandpa's curved dash Olds ran on). Gasoline as a motor fuel (every pump still has the warning that it is "to be used only as a motor fuel") diverged from plain-old gasoline somewhere under 100 years ago, with the "plain old" stuff being left to power Coleman stoves and lanterns and the like (I've got a bunch of them - they work damned well). Remember the old gasoline blowtorches?
- Eric
If I recall, gasoline used to be pink, which I assume was because of the lead additive.
Now it seems to be yellow.
"White gas" can still be purchased as "Coleman fuel" in gallon containers at hardware stores.
As far as I know, white gas is essentially old-time gas from before they started adding additives (the sort of stuff your great-grandpa's curved dash Olds ran on). Gasoline as a motor fuel (every pump still has the warning that it is "to be used only as a motor fuel") diverged from plain-old gasoline somewhere under 100 years ago, with the "plain old" stuff being left to power Coleman stoves and lanterns and the like (I've got a bunch of them - they work damned well). Remember the old gasoline blowtorches?
- Eric
May 27th, 2011, 06:58 PM
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Amoco's premium was unleaded and the necessary octane rating was achieved through additional refining steps. High-conversion refining is of course more costly. I don't know why Amoco chose high-conversion refining rather than additives to raise the octane rating back then, but I do recall they marketed Amoco premium as less harmful to engines due to no "lead build-up". I think most marketing based on quality was hokum. Some brands claimed they "cleaned' up your engine, or added performance through mystery ingredients like "techron". Today even premium gasoline is just a commodity. All you get is the minimum octane required to legally market as "premium". In fact, a really efficient refinery will minimize "octane giveaway"...if it says 91 octane, that's what you get. Sloppy refineries are forced to overshoot to make sure they don't run the risk of a big batch that tests 90.8 or something at the lab before it hits the pipeline or truck rack. Essentially, phase out of tetraethyl lead forced all refiners to use higher conversion steps, just as Amoco did in the late '50's.
May 27th, 2011, 07:03 PM
#30
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Great explanation!
As far as "lead build-up," I can remember having to chip the lead crap off my spark plugs every now and then, and having to blast it off the backs of valves when doing rebuilds.
- Eric
As far as "lead build-up," I can remember having to chip the lead crap off my spark plugs every now and then, and having to blast it off the backs of valves when doing rebuilds.
- Eric
May 27th, 2011, 08:39 PM
#31
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I have been running my engine on unleaded premium for over 20 years without harden seats and without any valve seat problems.
I have raced my car with both Sunoco & Amaco premium 93 octane pump gas and my car always run quicker & faster with Amaco 93 octane pump gas.
But now I buy Sunoco gas and my car doesn't run as quick or as fast as did with Amaco gas but everything and everybody that eats, sleeps and lives in or around the Gulf of Mexico appreciates that, I'm sure.
I have raced my car with both Sunoco & Amaco premium 93 octane pump gas and my car always run quicker & faster with Amaco 93 octane pump gas.
But now I buy Sunoco gas and my car doesn't run as quick or as fast as did with Amaco gas but everything and everybody that eats, sleeps and lives in or around the Gulf of Mexico appreciates that, I'm sure.
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