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Octane

Hobbit said:
well this question i can answer - i had to use 95 octance fuel the other day and under hard accel the knock sensor struggled to stop all knocking, and i managed to get 98/99 today and the knock has gone and the accel is back :D
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Isn't octane measured differently in the U. K.?
 
There is a misconception about octane.
Too many people think that the higher the octane the better the gas. Simply not true. Octane is simply the rate at which the fuel burns and the higher the octane the slower the fuel burns. It is also stated as a fuels resistance to pre-ignition. Any engine requires a certain fuel octane based on the combination of compression ratio and ignition timing. You should use the lowest octane that the engine will use without pinging. That will give you the most power and make the smallest dent in your wallet. Using a higher octane than that will just waste your money and reduce your power. Do any research on octane and you will find this to be a fact.
Obviously, you should start out with the octane rating suggested by your manufacturer.
I have used 87 in my 2001 Wide Glide, because I had no choice, and my bike didn't like it much but it ran ok if I didn't push it hard. I have also used 94 because I had to and it ran no better than the 91 I usually use. I have also used 89 and found it worked just fine. At most stations, you don't have all these choices, but for my bike, I wouldn't use 87 or 94 unless I had to. Here are 3 links to more in-depth explanations of octane and what it is and what octane you should use .

What is High Octane Fuel?

Higher Octane Fuel, Worth The Cost?

CanadianDriver Auto Tech: Should you use high-octane Premium gasoline?
 
had to use 87 in my shovel a ways back because i was to dumb to look in the tank before i left. didnt rerally notice a differance. maybe the old shovels dont care but i use 93 in the shovel, ironhead, and the tc. not sure what the older motors called for or if there was even much of a choice back then.
 
Intake valve closing point must be taken into account when computing Compression Ratio's.

Your actual Compression ratio can Not simply be calculated by a "piston ratio" number or volume size differences.
 
In Venezuela the only unleaded is 95 , i tried the 91 leaded and she just pinged when rollin on it , i use 95 and a dash of Marvels
 
The 100LL av gas may soon not even be sold, Thanks to our "friends" in the EPA, they are trying do away with it even though NO sutiable replacement has been found...the EPA attiude is "to (EDIT) with them" to the thousands of aircraft owners that have big bore/high compression aircraft....it has been pointed out to them, that by Federal law, they can't deprive these owners of the use of their property, but again it is "tough"...we can ignor the law....we are the Feds....



Please read this...

A Friendly Reminder - Harley Davidson Community

 
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rhino said:
had to use 87 in my shovel a ways back because i was to dumb to look in the tank before i left. didnt rerally notice a differance. maybe the old shovels dont care but i use 93 in the shovel, ironhead, and the tc. not sure what the older motors called for or if there was even much of a choice back then.
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Stock shovels never burned all of the gas anyway because the flame front could not get past the piston dome tho they made good power and really liked to be stroked and dual plugged:s
 
Hoople said:
You can still get Leaded fuel in Venezuela?
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We just got unleaded about 3 years ago , my panhead loves the leaded but my twin and evo prefer the 95 , sometimes i add a little 110 avgas from my buddy at the airport for a treat
 
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