Alright How does octane level in gas affect its buring properties. does higher octaine make it harder or easier to combust and does it make it burn hotter or colder. I have been told one thing by somebody and then my friend insists the opposet so whats the verdict?

 

The higher the octane rating, the slower it burns. Therefore reducing combustion temperatures and preventing engine knock.

Need I say more?

 

Well this is a long story but I will try to make it short. The higher the octane (in gasoline) the harder it will be to pre-combust. In other words, it won't try and start a fire in another part of the cylinder from high cylinder pressure. If it does, these two pressure waves will collide and cause the ping you hear.
Octane does not really have anything to do with how hot (BTU value/ lb of fuel)something burns. Some fuels burn very hot, (have a high BTU value/lb of fuel) but have a low octane rating (diesel). Some fuels have a low BTU rating but have a high octane rating. (Propane)
It gets even more confusing. Nitromethane has very low BTU's/lb of fuel and is very low octane.
Now if you want to talk about combustion chamber BTU's then the fuel with the most BTU's/lb and with the highest oxygen content will win. If I remember right, nitromethane has over 50% oxygen content contained in the fuel itself. That is why it produces so much power. It's easier to pump liquid than a gas, and since nitromethane is a mono propellent you don't really need any air to pump to make a lot of power.
Most if not all racing gas'es on the market have more BTU's than a pump gas. So if tuned right, the racing gas will make more power than a pump gas. Notice I said "if tuned right". All race gas'es have a higher octane rating than a pump gas. This is not what you want if you have a low compression engine, but you do want the higher BTU's (energy). So if you bump the timming (to off-set the slow burn) on your low compression engine, you will "usually" make more power than a pump gas.
In short, if you dump some octane booster in pump gas and expect to make more power, it won't happen, because the base stock gas has the same BTU's. But if you start out with race gas, it has both higher BTU's/lb and higher octane than a pump gas, so if tuned right, it will make more power.
I hope somewhere in this tirade I answered your question?!!!!! Like I said, it gets really complex, and people make a living writing about this stuff.

 

WOW the colors man.... the colurs..........

 

yea i thought it was slower the guy tells me higher octane runs hotter so he is running 87 instead of 93 in his Quadzilla. thanks

 

Now I will ask one question that I hope I know the answer to but will ask for verification. I have been told and follow, that when mixing reace gas 50/50. I was told if I use low octane (87) it will give better performance then high (91's) octane because of the chemicals that regular pump gasses use. I was told if I use a high octane pump with reace gas that it will actually make my overall octane lower then if I use low grade pump gas in the mix.... sound like the real deal... hel at least it is cheaper. Plus I ping on the good stuff from the pump and only ping when beating the hel out on the very top end every now and then with the 50/50 mix. I am using a 50-1 ratio.

ca

 

Octane of gas is fractional. In other words: lets say you start out with a gallon of 92 pump gas and add a gallon of 112 race gas to it, your 50/50 mix will come out with a 102 octane rating fuel. Or you can start out with a gallon of 90 pump gas and add a gallon of 114 race gas and you will still end up with a octane rating of 102. You can play with this combination to make endless mixes to fill your needs. So to answer your question, your pump gas base stock can be anything, but you will have to add more race gas to it to bring up the octane if you start with a low octane pump gas.
Chromezilla if I were you (and I do this) here is what I would do. If you are right on the edge of detonation (and you make it sound like you are) with pump gas, I would buy a gallon of race gas, then buy a gallon of pump gas, and then just buy a 5er to mix it in. Mix 3/4 pump gas with 1/4 race gas in your 5er. Do the shake shake shake and pop the mix in your quad. Got any detonation? Cool, now 4/5 to 1/5 in a new 5er. Get the point? Just do this until you hear detonation and then take it back up one mix fraction. That way you have the most bang for the buck. Write this mix down somewhere in case you bump your head or have one to many beers. [img]i/expressions/face-icon-small-happy.gif[/img]
Another way you could go is go down to a hardware store and buy a gallon of toluene. Mix 1 gallon of toluene with a 5er of pump gas. No detonation? Then go with a 1/2 to a 5er. This works very well when you are close to detonation with pump gas. This is a cheap and easy way to go.

 

Thanks ... I will try that. I will report back findings.

ca

 

Octane has 8 carbon bonds (oct=8) Heptane has 7 carbon bonds (hep=7). Octane is resistant to ignition when compressed. Heptane ignites easily when compressed. Pump gas of 87 octane has the properties of a theoretical fuel made up of 87% octane and the remainder heptane. Theoretical because you can achieve an 'octane rating' of 87 or any other number by adding all sorts of crap to gas like methanol, ethanol, MTBE, etc... Vinsons SHOULD run better on higher octane than Eigers because they have a higher compression ratio and theoretically need fuel that is less prone to pre-combustion.
This property to resist combustion from just pressure is why the drag racers can super-charge their already high compression engines without nuking their pistons. Super-high octane numbers mean you can compress the HE!! out of it w/o it igniting until there is an actual spark.

Hopefully that little bit more information was at least interesting.

 

aksafari thats exactly what i needed to hear thanks to all now i can go tell him he is wrong and have some backup for it