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Re: 110 Leaded Octane fuel
Michael,
GIVE UP! That means you are a quitter. This is a forum where people share knowledge and try to learn from each other, not try and make people look like idiots. I have held a Federal mechanics licence since the mid 70's and have been trusted to inspect any civilian aircraft including some military experimental aircraft. From the smallest to the jumbo jets. I am still active in this field and have been there and done that. Induction, fuel, ignition are sacred areas and I have actually been there to do tests and work as a expert witness. I was requested by the man who held the highest office in our country to work for him, not to mention heads of other countries. I have had a shop since the 60's and burned all kinds of fuel including nitro. I went a bit further than paper for test results.
I cherish this forum because of the experience that is shared here that is not on paper. Guys that have worked in the auto industry for years to the guys that just tinker and share their tips. I have learned a bunch here that is not on paper or in books.
You have disputed every thing I have ever posted for some reason and have discounted me when I share my actual experience for others to consider. I listen to every one here that has actually done what they talk about because not everything in print is correct. I consider myself a strong average and not a idiot. The forum is for sharing and not argument.Comment
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Re: 110 Leaded Octane fuel
Gene -
I think AV gas is 100LL
Sunoco does make a TEL blended 110 (blue dye).
But I do have a general question on 100LL.
I heard somewhere along the way it was not good to burn it all the time.
Something about how the fuel was engineered burn (high altitude vs. sea level..)
Is there truth to this?
BillComment
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Re: 110 Leaded Octane fuel
...JUST ANOTHER MYTH!!!
Any fuel that can be reasonably called "gasoline" is suitable for spark ignition engines. The only thing you need be concerned with is that the octane number is sufficient to prevent significant or sustained detonation, especially on a vintage car.
Modern cars - say going back about 20 years - have detonation sensors and electronics that will retard the spark advance map to keep the engine out of detonation if a lower than recommended octane fuel is used, and the only downside might be slightly less WOT power and slightly increased fuel consumption since spark advance may be less than optimum.
Avgas is blended to have a higher distillation curve - at any given temperature a lower mass fraction of the fuel's components are at /above their boiling temperatures compared to mogas - to prevent vapor lock at high altitude were ambient pressure is lower. The same is generally true for race gas. Apparently this got misconstrued to:
"[...s]omething about how the fuel was engineered [to] burn (high altitude vs. sea level..)"
It has nothing to do with how the fuel "burns". It's purely a distillation curve issue.
The only downside of this in automotive applications is, maybe, slightly tougher cold starting, but since most vintage car owners who use avgas or race gas don't do cold starts in very cold weather, it doesn't appear to be a problem in most situations; and on the upside it usually "solves" vapor lock and percolation problems that some cars suffer with E10 that has a greater mass fraction of components boiling from about 140-200 degrees because of the ethanol, which boils at about 170F.
Avgas and race gas have distillation curves somewhat above the mogas blends in the attached graph, particularly in the lower end. The avgas midpoint (50 percent) is about the same or a little above the traditional non-ethanol summer blend, but the curve is higher below this temperature, which is why it's more resistant to percolation and vapor lock.
DukeLast edited by Duke W.; October 11, 2016, 10:01 AM.Comment
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Re: 110 Leaded Octane fuel
Another benefit that became known over time was that Tetraethyl lead kept valve seats from becoming worn down prematurely. Exhaust valves, in early model cars, that were subject to engine knocking tended to get micro-welds that would get pulled apart on opening. This resulted in rough valve seats and premature failure. Lead helped fuel ignite only when appropriate on the power stroke, thus helping eliminate exhaust valve wear and tear. Bottom line, high octane leaded fuels are good for older high compression motors, but detrimental to our air.Comment
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Re: 110 Leaded Octane fuel
Originally Posted by Gene Manno (8571)
Trying to stay with the topic, I'm assuming the original poster is referring to aviation fuel since he refers to 110 octane but says nothing about aviation. May be not. We have Sunoco blue 100 octane aviation fuel near by. Is not aviation fuel a longer shelf life compared to pump gas?
A pilot friend of mine seems to think it does. Aviation fuel does smell nice running out the exhaust.............!
Well, Does aviation fuel a longer shelf life (sitting in the car) compared to pump gas?Comment
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Re: 110 Leaded Octane fuel
VP makes 110 AKI leaded fuel
as does Rocket
Obviously being leaded, they are not legal for street use.
Rocket is the publisher of several interesting tech articles discussing 'racing' fuels and their numerous myths and misunderstandings. Well worth reading the ones that deal with octane.
I've heard the extended shelf life story for almost 40 years but cannot find any credible research to back it up. On the other hand I've never had stale gas problems when using straight pump gas.Comment
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