What octane is best, and why

[Bjorn]

QUOTE="Redfin, post: 1226042, member: 159"]Found the finished car but couldnt find a vid of it running on track.

Impressive regardless.

I believe he's still working on it. There is a vid of the engine running after completion.

[/QUOTE]
Wath octane?

 

[drf256]

Great thread. Dispelled some myths for certain.

I’m gonna venture to postulate that the cooling effect of a fuel probably has more to do with power output in a chainsaw than its ability to burn a microsecond faster or slower.

 

[Likesaws]

Great thread. Thanks

 

[huskyboy]

I noticed more difference in gas brand affecting how the saw ran and the carbon buildup than from different octanes. I think it is best to go to a gas station that is busy... they will be refilling the tanks more often. Fresher fuel is better. Just my opinion. Would be interesting to see that tested more scientifically... rather than my speculation from what I have seen.

 

[Bjorn]

Hello everybody. I have a Lawn mower that I use to run at 95 octane With 10% ethanol and it would dye every time a little longer gras needs to cut of. Then I changed to Shell v-power 98 octane and 5% ethanol and now it dont dye as fast, stronger and hold rpm better, more torque. So I Will Continue running high octane fuel in all my outdoor equipment.

 

[Maintenance Chief]

Honestly if you want to burn any tyoe of gas in your power equipment you should have that option, but practical applications are variables we are not prepared to definitively say that one is better than the other.
Basically as with most things in life you get out what you put into with it.

 

[Woodpecker]

Just use a Fúckknows what size Whitworth

shortened to *f-wordwit size here in my neck o the woods.

 

[Bull Mountains]

extasec,,, I know where your coming from. Different crudes are of different compositions. And depending on what you want to make... you'd boil and mix different crudes. Even to say you'd boil abit then mix with another bit that’s been boiled .

I remember a little from general chemistry and then. A bit more from chemical chemistry breaking and forming bonds in the petrochemical industry. been a while thou

Its alot more than variability in the crude feed. Process variability based on ambient temperature, changes in catalysts, changes in heater temps, changes in reflux temps. There are really such a wide variety to variable process wise that can be changed its mind boggling. For instance the unit I work in can simply add different catalyst additives or promoters to increase olefin make and lower gas make. Or we can change temps in or main column to increase diesel draw.
The point being gasoline make up changes by the hour. I see this very day in the lab analysis of the products my unit makes.

 

[Bull Mountains]

Hello everybody. I have a Lawn mower that I use to run at 95 octane With 10% ethanol and it would dye every time a little longer gras needs to cut of. Then I changed to Shell v-power 98 octane and 5% ethanol and now it dont dye as fast, stronger and hold rpm better, more torque. So I Will Continue running high octane fuel in all my outdoor equipment.

I would bet your mower actually made more power on 10% ethanol fuel. Oxygenated gas typically does make more power.

 

[Bull Mountains]

I noticed more difference in gas brand affecting how the saw ran and the carbon buildup than from different octanes. I think it is best to go to a gas station that is busy... they will be refilling the tanks more often. Fresher fuel is better. Just my opinion. Would be interesting to see that tested more scientifically... rather than my speculation from what I have seen.

Gas is a tradable commodity. I can assure you every brand truck you can imagine fills up at refinery I work at.
It is smart to fill up at a station that goes through alot of product.

 

[Lightning Performance]

You're in the U K. Just use a Fúckknows what size Whitworth instead.

They have those old fugged up British sizes. I have few of those wrenches here. What do they measure BTU's... da fook! Lol

Great thread. Dispelled some myths for certain.

I’m gonna venture to postulate that the cooling effect of a fuel probably has more to do with power output in a chainsaw than its ability to burn a microsecond faster or slower.

Maybe you ment cleaning affect to keep out carbon? Just a thought.

Hello everybody. I have a Lawn mower that I use to run at 95 octane With 10% ethanol and it would dye every time a little longer gras needs to cut of. Then I changed to Shell v-power 98 octane and 5% ethanol and now it dont dye as fast, stronger and hold rpm better, more torque. So I Will Continue running high octane fuel in all my outdoor equipment.

Your just on the borderline of burning down the motor probably. If you went up in octane you went down in burn rate or worked gained from those units. By doing that you cool off the whole motor because of passing more gas and heat out the exhaust. Try going down in octane and see if you get even less power but signs of aluminum flash on the spark plug. Old racers trick to read a plug, a clean fresh one, after the motor is warmed up. Real easy to spot flash-over on a white insulator or bare steel with a dark color. This gives direction with octane vs mix ratios. Follow the signs don't ignore them. You might need a lesser fuel octane and a richer condition. It all goes to hell very quick at the track if you miss the tune and the weather is cooling off as you run. Dry air is easier to "tune in" so remember that.

 

[Bull Mountains]

Great thread. Dispelled some myths for certain.

I’m gonna venture to postulate that the cooling effect of a fuel probably has more to do with power output in a chainsaw than its ability to burn a microsecond faster or slower.

20 years ago shifter cart racers where using fuel with a bump in the upper portion of the distillation curve for this very reason.

 

[davidwyby]

I made it. I skimmed a lot.

I missed the reason for the creation of this thread.

I thought we already settled this the other day when I tried to use VP110 to avoid eth and it slobbered out the muff of the 6100 and lowered power. I gave it a second chance milling in the 395...coked up the plug, didn’t want to hot/warm restart. Back to 87. I think canned runs the best. Might try 90-whatever from the pump next time.

 

[drf256]

So you guys like it in the can?

 

[FergusonTO35]

The more refined, premium fuels such as 91 and 92 octane seem to have a better shelf life than the lesser, cheaper cousins, and there is the ethanol issue with lower grade fuels. This is the primary reason why I run premium verses the other that usually give just a little more power. Chainsaws and other power equipment have a tendency to sit a long time with fuel in them. I've had chainsaws sit in my garage for 2+ years with BP premium start with no issues.

That's my thinking, you usually get what you pay for and the extra cost is minimal considering how 2 stroke is such a tiny part of my fuel purchases.

 

[Larry B]

Back in the day (1974) when i worked a summer at a small airport. We did service on a plane called a howard 500 conversion. It needed 100/130 octane AV gas which was not available. It had a alcohol/water injection system it used for full power during takeoffs.

 

[whitesnake]

I've heard 100ll really doesn't contain that much lead. And back in the day all gas was "lead" cars, mowers, blowers, etc. Many of those people are still alive? Opinions?

 

[Bull Mountains]

I made it. I skimmed a lot.

I missed the reason for the creation of this thread.

I thought we already settled this the other day when I tried to use VP110 to avoid eth and it slobbered out the muff of the 6100 and lowered power. I gave it a second chance milling in the 395...coked up the plug, didn’t want to hot/warm restart. Back to 87. I think canned runs the best. Might try 90-whatever from the pump next time.

Depending on what specific 110 it may have ran like crap because the fuels distillation curve isnt matched to a two cycle. As a result the fuel passes through the engine without vaporizing and goes out the exhaust unburnt.

 

[Bull Mountains]

I've heard 100ll really doesn't contain that much lead. And back in the day all gas was "lead" cars, mowers, blowers, etc. Many of those people are still alive? Opinions?

It's called 100 Low Lead, but its anything but. It contains more lead than leaded auto gas ever had.
Lead wont kill you, but it will degrade your cognitive ability. Even in small amounts.

 

[davidwyby]

Depending on what specific 110 it may have ran like crap because the fuels distillation curve isnt matched to a two cycle. As a result the fuel passes through the engine without vaporizing and goes out the exhaust unburnt.

Yup.