Octane question

[sean donato]

I don't own newer saws all my saws 066/660 even 661 used to run perfectly in 40 celsius all day after day never a problem with boiling fuel.
As soon as it gets up into like 35 celsius forget about it lol
I can put a cold fueled up not even started for the day saw in the sun for only 10 minutes and it will not start that's all it takes. It's getting that way pump fuel is almost unusable in summer for me, the rest of my family have the same troubles and a few wood cutters I've talked to say the same thing.

That's too bad. Wonder if it's a regional fuel quality thing.

 

[rogue60]

That's too bad. Wonder if it's a regional fuel quality thing.

I'm in a small country town so yeah they probably say send them the **** fuel who cares lol
I will add they run fine in winter- mornings 0 to 25 celsius in the day.

 

[sean donato]

I'm in a small country town so yeah they probably say send them the **** fuel who cares lol
I will add they run fine in winter mornings 0 to 25 celsius in the day.

Wonder if they ever change over to the sumer mix? Big difference when we get up around 60*f if you got winter duel yet. Just verging for issues.

 

[rogue60]

Wonder if they ever change over to the sumer mix? Big difference when we get up around 60*f if you got winter duel yet. Just verging for issues.

As far as I know we don't have a summer or winter mix here idk if we do they must be selling the winter mix year round it's rubbish..
Actually my understanding was pump fuel isn't even designed for hand held equipment anymore it's designed for new vehicles running very high fuel pressure this raises the boiling point and things like fuel lines shielded from heat and a constant cycling of the fuel back to the tank. All this allows fuel companies to remove the expensive anti boiling additives that are no longer needed. Only problem with this hand held equipment on the most part hasn't changed in design from running the pump fuels with all the anti boiling additives of yesterday..

 

[lone wolf]

As far as I know we don't have a summer or winter mix here idk if we do they must be selling the winter mix year round it's rubbish..
Actually my understanding was pump fuel isn't even designed for hand held equipment anymore it's designed for new vehicles running very high fuel pressure this raises the boiling point and things like fuel lines shielded from heat and a constant cycling of the fuel back to the tank. All this allows fuel companies to remove the expensive anti boiling additives that are no longer needed. Only problem with this hand held equipment on the most part hasn't changed in design from running the pump fuels with all the anti boiling additives of yesterday..

IDK but it sure does make life harder.

 

[ZeroJunk]

Diet is more important than exercise sugar and carbs can lead to diabetes. Eliminate sugar and processed carbs and things will get better.

I have been walking three miles a day since 2001. Hardly ever miss a day. I could stand to lose about 10 pounds. I seldom eat anything with sugar in it. But, I am in to bread and potatoes LOL

 

[lone wolf]

I have been walking three miles a day since 2001. Hardly ever miss a day. I could stand to lose about 10 pounds. I seldom eat anything with sugar in it. But, I am in to bread and potatoes LOL

Stay far away from bread that aint good for you believe it or not or at least cut down on it. Especially if you show any pre diabetic symptoms. Sugar is for sure a killer.

 

[ZeroJunk]

Stay far away from bread that aint good for you believe it or not or at least cut down on it. Especially if you show any pre diabetic symptoms. Sugar is for sure a killer.

White bread starts turning to sugar before it even leaves your mouth.

 

[Bill G]

As far as I know there's no standard pump color in the USA that everyone has to follow. We can make a few assumptions based on our area but that may not be true everywhere. What really boggles my mind is we have standard colors for fuel containers but not the pumps we get the fuel from. We have to refer to the labels on the pump for that.

I am sure you are correct in the fact that there is not a standard that must be followed. In all honesty we really do not more regulations. The woman I referenced was in the wrong. She made an assumption based on color and should have been bright enough to look at the pump. I do know I have never seen E-85 ever sold from a pump that was not primarily yellow and had a yellow hose. I am not saying that is a regulation but it appears to be standard practice, at least here.

 

[sean donato]

I am sure you are correct in the fact that there is not a standard that must be followed. In all honesty we really do not more regulations. The woman I referenced was in the wrong. She made an assumption based on color and should have been bright enough to look at the pump. I do know I have never seen E-85 ever sold from a pump that was not primarily yellow and had a yellow hose. I am not saying that is a regulation but it appears to be standard practice, at least here.

Smae here for e-85, yellow. E-15 gets blue for some reason.

 

[Bill G]

Smae here for e-85, yellow. E-15 gets blue for some reason.

I am not sure on E-15 here. I am not even sure they can sell it in Iowa right now. I know a few years ago there was a huge fight in the legislature over when (time of year) it could be sold. I just found and old article that says it will be mandated to be available in all newer stations in 2026.

A key tidbit from the article is........Still, the law is expected to greatly expand the availability of E15, which is currently available at a fraction of Iowa's gas stations and truck stops. Most stations sell gasoline with no ethanol and gasoline with 10% ethanol blended into it.......................

This is in Iowa corn country USA and they do not force anyone to buy any specific fuel. We have choices here and that is great.

https://www.desmoinesregister.com/s...g-gas-stations-offer-e-15-ethanol/9570674002/

 

[sean donato]

All our pump fuel is e-10, besides rhe few places that sell e-free and higher content.

 

[Bill G]

All our pump fuel is e-10, besides rhe few places that sell e-free and higher content.

I support ethanol but there are situations it does not belong in, one of which is engines that sit. I support folks right to choose and not be mandated to do things. I know the article I posted says E-15 will be mandated in 2026 but that does not mean you must use it. The mandate is telling larger gas retailers they must simply make it available for people to choose. If it does not sell the stations do not have to fill their tanks. There is always more than one way to skin a cat.

 

[sean donato]

I support ethanol but there are situations it does not belong in, one of which is engines that sit. I support folks right to choose and not be mandated to do things. I know the article I posted says E-15 will be mandated in 2026 but that does not mean you must use it. The mandate is telling larger gas retailers they must simply make it available for people to choose. If it does not sell the stations do not have to fill their tanks. There is always more than one way to skin a cat.

They mandated it for use in all our gas years ago, no choice about it.

 

[lone wolf]

I have been walking three miles a day since 2001. Hardly ever miss a day. I could stand to lose about 10 pounds. I seldom eat anything with sugar in it. But, I am in to bread and potatoes LOL

Carbs turn into sugar look it up. 10 lbs drop in weight might give you at least a 10 point drop in blood pressure. Also less snoring.

 

[esshup]

Find an airport near you

http://100ll.com/
It's $5.90/gal nearby here now.

It does have lead so don't spill it on yourself or huff the fumes.

$6.33/gal at the airport 12 miles to the West, $4.63 at the airport 10 miles SW of here. 110LL. That's what I use in 2 of my 3 saws. The other one that won't respond to tuning to run on it sees 93 octane E-Free that I have to get 25 miles East of here. I flat out refuse to run ANY type of ethanol blended fuel in any of my motors. I'm tired of the issues that it causes.

 

[ZeroJunk]

Carbs turn into sugar look it up.

Yeah, I know. What I majored in back in the day.. Pretty insignificant diploma. But, I have one.

 

[Bill G]

They mandated it for use in all our gas years ago, no choice about it.

That is one of the many reasons I am not fond of mandates. I like ethanol but for the government to take away an alternative is not right. This is supposed to be a "free country"

 

[bwalker]

Nothing you have presented discusses any such facts. Except for one enthusiast publication, which you have scorned as a source of information.





Quite true. You would, however, need to read that article to see the experimental conditions under which the tests were conducted.





Huh? Where did I make any such claim. Density has little to do with molecular weight of hydrocarbons, to which I have indeed referred. ONLY A NON-CHEMIST WOULD MAKE THAT MISTAKE. And I don't think I ever made any references to "stability"





Fluff and nonsense. Again, I wasn't discussing "density". Why again are we talking about lighter hydrocarbons?





Your concept of "stability" is a misnomer. What all your physics nerds are describing is the conditions that lead to a flame speed that is accelerated beyond the speed of sound by the reaction rate and the higher pressures under cylinder compression. There is no "stability" issue. The chemical reactions are the exact same as when there is no detonation. The only difference is the speed at which the reaction occurs. Like almost all chemical reactions, it happens faster at higher temperatures and pressure. Each fuel is a chemical, and each chemical will have it's own specific reaction rates for each temperature and pressure involved.









Well for starters, ethanol isn't generally considered "a hydrocarbon", it is an alcohol. As such, it is less energetically inclined to combine with oxygen, since it is already attached to one oxygen molecule.



I did find this: "The octane rating of pure ethanol is 100. What's interesting is that when ethanol is blended with gasoline, it performs as if its octane rating is 112, making ethanol a very effective octane booster when used in gasoline."



What you should also understand is that because it might burn faster than iso-octane, it does not produce as many gas metabolites after burning. Which will have the net effect of not increasing the pressure inside the cylinder as much as other fuels, and it will consequently have a greater resistance to detonation under identical physical conditions as gasoline.



Something to think about:

As you have already pointed out, gasoline is composed of a lot of different chemicals. Lets mix in some water!

Water would have a flame speed of 0, at least until it were dissociated into hydrogen and oxygen. Then it becomes the best rocket fuel known, with a monumentally fast flame speed. And we all know how well water prevents detonation when we add it to the gas tank, so I'd guess it has a pretty damned high octane number as well. Until you "dissociate" that highly stabile water molecule into rocket fuel. I'll bet the octane number of liquid oxygen & hydrogen is in the negative thousands.



Allow me to suggest that much like water, comparing alcohol to other hydrocarbon fuels isn't probably a valid comparison.

Density is very important to refining. As you move up the draws in a distillation column density decreases along with boiling point. Octane levels very by the nature of the chemical bonds of the molecule in question and don't track like this.
If you look at the molecular weights they likewise track down as you move up the column for the common HC's in the C3-C10 range. Of course it would be possible for this not to be the case but the carbon to hydrogen ratio would have to really be out of wack as carbon has a molecular weight many times than hydrogen.
Again, your knowledge of organic chemistry as it pertains to refining is lacking. Your talking theory, but you lack the expiereance and industry knowledge to put that theory to use. Not at all uncommon for someone with a degree, but no expiereance.
Your issue with the term stability isn't pointless. It's not a great description, but wether you refer to it as "stability" or "grace under pressure" or some other lay term it's not a bad description in lay terms. This applies only to the flame and not ignition. The chemical reaction are not the same between normal combustion and detonation either. The formation of active radicals doesn't occur in normal combustion. With respect to the speed aspect you mention. This occurs only when detonation starts and isn't indicative of what happens in normal conditions
My mention of alcohol was only made to suggest that slower flame speeds do not suggest high octane and indeed they don't.
I've provided enough information to you that you should be able to understand that anything you do to slow down flame speed increases the risk of Detonation. It's pretty evident, really and if you understand detonation, where it occurs, conditions it occurs under and how a combustion engine functions its pretty intuitive as well.

 

[pdqdl]

White bread starts turning to sugar before it even leaves your mouth.

All carbohydrates do. That's the amylase enzyme in your saliva breaking down those complex sugars into simple ones you can taste. If we didn't taste those sugars, we wouldn't like those starches nearly so well.

Same thing is true for toasting those carbs. Toasting starts that digestion well along the way when they are browned. This is even more true of the meats, as they too are broken down by cooking into the amino acids that taste so good, although amylase doesn't act on the proteins. That's a job for stomach acids.