Lead gas additive

[PlymCrazy]

Any of you guys still use a lead additive in your gas you can recommend? ‘55 265 Chevy and former owner added it to the gas regularly he indicated. I never asked him what brand he used nor where he bought it from. This is a first for me.

 

[33 IMP]

The lead additives, IF it's real lead are very dangerous. Don't get it on your hands.
I use 100LL avgas, primarily for its octane rating, and cause I can get it, but if you're worried about the exhaust valves (considering how many miles collector cars are really driven, I wouldnt) a gallon or so of avgas is what I would do, per tankful.

 

[Demonic]

Too much over the counter stuff in your tank can turn your plugs orange, and possibly foul them.

 

[dadsbee]

 

[khryslerkid]

Whether I'm using 10% ethanol during the summer months or using non-ethanol for winter storage, I use the Staybil 360. One oz per 5 gal of fuel. Has the protection that I'm looking for and protects the gas from deteriorating.

 

[Photon440]

I don't think that STA-BIL, or any other brand, has any actual lead in it. It used to be common to see TEL additives but they're using substitutes such as manganese carbonate. To have lead - tetraethyl lead, or TEL, it has to be first made available to be added, and there are no American companies that produce it. There is only one place in the world that makes it (for the aviation fuel market) and it is INNOSPEC in the UK. They specifically state that they will not sell to the general public or to third party fuel treatment companies.

If you see online articles talking about real lead additives, they're generally dated at least several years ago when it was still possible to buy them.

 

[mrhemi]

Any of you guys still use a lead additive in your gas you can recommend? ‘55 265 Chevy and former owner added it to the gas regularly he indicated. I never asked him what brand he used nor where he bought it from. This is a first for me.

Yes, it is called 100LL Av Gas or leaded racing fuel, at a 1:4 ratio with premium unleaded.

 

[dadsbee]

 

[PlymCrazy]

The lead additives, IF it's real lead are very dangerous. Don't get it on your hands.
I use 100LL avgas, primarily for its octane rating, and cause I can get it, but if you're worried about the exhaust valves (considering how many miles collector cars are really driven, I wouldnt) a gallon or so of avgas is what I would do, per tankful.

Probably 500 miles per year realistically.

 

[Dennis H]

Used to, but no ill effects driving without an additive. 91 unleaded pump here for at least 10 years.

 

[PlymCrazy]

So I find myself questioning whether I really understand the purpose and/or significance of the lead additive, or leaded gas back in the day, period.

I always understood the lead softened the impact of the valves when they closed in the seats. And if not used it leads to damage of those components, in particular the seats.

Please correct my thinking as you guys see necessary.

 

[topside]

I've never had an issue from normal gas in a mild street engine like a 265 or whatever.
The high-CR engines get 110LL or 110 race fuel mixed in.
Been using Sta-Bil for many years, and the cars start & run fine even after a year or so of sitting.

 

[#41]

Used to, but no ill effects driving without an additive. 91 unleaded pump here for at least 10 years.

I ran unleaded premium in my Charger from 1987 - 2010 (+/-). I had ported the 906 heads and wanted to save them, so I pulled them to put stock heads on before selling the car. They were ruined.... the exhaust valves were so sunken into the seats I tossed them in the scrap bin. That was maybe 20,000 miles of driving.

 

[AR67GTX]

This is the good stuff for octane boosting with real ltetraethyl lead. But very expensive, ver hazardous and not considered street legal.

I still have some of this but with careful tuning and adjusting of advance curves I’ve pretty much tamed my cars needs for more octane and just run 93 ethanol or 91 non-ethanol with no issues. I don’t really consider lead to be an issue on a car that’s not getting 15,000 miles a
year put on it and not towing a load or lugging the car a lot. And there’s less fouling of plugs and combustion chambers to worry about.

edit: I see some are still seeing issues of exhaust valve recession. I don’t put enough miles a year on my cars to worry about that. But maybe some still do.

 

[mrhemi]

TEL served two purposes, increasing octane and protection against valve seat recession in earlier engines that did not have hardened exhaust valves and seats. If your car runs on 91 octane without detonation you don't need TEL. The valve seat recession problems are more prevalent in engines that run continuously at a sustained high power setting. Cruising in your hot rod is not a continuous high power setting, so you will not likely experience valve seat recession. Aircraft piston engines on the other hand operate at continuous high power settings (+50%) so still require the TEL in 100LL Av gas. Some marine applications are another example. I have a 1989 Ski Nautique (competition ski boat) equipped with a Pleasurecraft Marine inboard (351 Ford based). Towing a skier at competition levels is always a high power setting (+50%). Even in 1989, the OEM manufacturer recommends leaded fuel or a lead substitute (which are non effective). So even my boat gets a "tip of the can" of some good leaded fuel occasionally.

 

[33 IMP]

The way I understand it, your idea of why the use of a lead substitute/additive is correct.... for a daily driven old car without hardened exhaust seats. At twenty thousand miles a year, I might worry about it. At 500 miles a year I might worry..... in 2050.

 

[mrhemi]

This is the good stuff for octane boosting with real ltetraethyl lead. But very expensive, ver hazardous and not considered street legal.
View attachment 1365820

I still have some of this but with careful tuning and adjusting of advance curves I’ve pretty much tamed my cars needs for more octane and just run 93 ethanol or 91 non-ethanol with no issues. I don’t really consider lead to be an issue on a car that’s not getting 15,000 miles a
year put on it and not towing a load or lugging the car a lot. And there’s less fouling of plugs and combustion chambers to worry about.

edit: I see some are still seeing issues of exhaust valve recession. I don’t put enough miles a year on my cars to worry about that. But maybe some still do.

When I still worked in a refinery and had access to the lab, we tested this stuff (with proper lab equipment and in a Waukesha knock engine). While it wasn't exactly "snake oil", the advertising was rather dubious at best as to the claimed results. Analysis found the product to be premium hydrocarbon containing 2 grams per gallon of lead. So, they were selling you a 32 oz. container of 100LL Av gas at 1000+% mark up. Mixed with gasoline at the recommended ratios did not produce the claimed results, however their advertising did not specify which decimal point or exponent of an "octane point" they are actually referring to.

 

[68BabyBlue]

Baby Blue (my never restored, never overhauled former '68 GTX) ran 68,000 miles on leaded premium back in the day, then switched to Amoco 93 octane unleaded pump gas in 1974 when my friend Bob acquired her. I did the same, later switching to other brands as unleaded became the mainstream fuel. When I parted with the car last year, the original engine still ran like new with 119,000 miles. Original valve seats, never used lead additive, or an octane booster. Car was never daily driven after hitting the 100,000 mile mark.

 

[RJRENTON]

The lead additives, IF it's real lead are very dangerous. Don't get it on your hands.
I use 100LL avgas, primarily for its octane rating, and cause I can get it, but if you're worried about the exhaust valves (considering how many miles collector cars are really driven, I wouldnt) a gallon or so of avgas is what I would do, per tankful.

IMO......Lead additive is:
Tetraethyllead, abbreviated TEL, is an organolead compound with the formula Pb(C₂H₅)₄. It is a fuel additive, first being mixed with gasoline beginning in the 1920s as a patented octane rating booster that allowed engine compression to be raised substantially.
Lead was added to gasoline in the United States for many decades in the form of tetraethyllead (TEL) and other forms of alkylate derivatives. As health-related effects of lead in gasoline became a major issue the use of TEL was phased out and completely eliminated in all US gasoline by 1996. It also renders the catalytic converter inoperative, The converter was introduced in 1975.
Tetraethyl lead, liquid appears as a colorless liquid with a characteristic odor. Flash point 163 °F. Density 14 lb / gal. Insoluble in water. Toxic by inhalation and by skin absorption.
A highly toxic compound used as a gasoline additive. It causes acute toxic psychosis or chronic poisoning if inhaled or absorbed through the skin.
The tetraethylead additive increased the octane rating of gasoline but when combusted, left behind a lead compound. Today's gasoline's are blended with alkaylates of propene, isopentanes, isobutanols thru a process using sulfuric acid. alkylation, in petroleum refining, chemical process in which light, gaseous hydrocarbons are combined to produce high-octane components of gasoline. The light hydrocarbons consist of olefins such as propylene and butylene and isoparaffins such as isobutane. An alkylation unit is one of the conversion processes used in petroleum refineries. It is used to convert isobutane and low-molecular-weight alkenes into alkylate, a high octane gasoline component. The process occurs in the presence of an acid such as sulfuric acid or hydrofluoric acid as catalyst.
Stay away from the over the counter octane enhancers......just buy 100 octane low lead AV GAS......you'll be better off. Thus ends the lesson for today......
BOB RENTON

 

[diesel_lv]

If you have easy access to 100ll avgas, use that as above. Otherwise, for simplicity sake when taking the car anywhere, I'd have a valve job done w hardened exhaust seats. Really not that expensive and never have to worry about it afterwards.