how high is too high octane
- Thread starter miggles
- Start date
Greg, to follow up on your detonation definition,
It is safe to say that if a nice JE is textured more like sandpaper and a little white in color rather than it's pretty polished appearance that it has gone through the softening phase in that region of the crown, and it is now dead. correct?Adjuster said:
Avgas is currently available in several grades with differing maximum lead concentrations. Since TEL is a rather expensive additive, a minimum amount of it is typically added to the fuel to bring it up to the required octane rating so actual concentrations are often lower than the maximum.
* Avgas 80/87 has the lowest lead content at a maximum of 0.5 grams lead per US gallon, and is only used in very low compression ratio engines.
* Avgas 100/130 is a higher octane grade aviation gasoline, containing a maximum of 4 grams of lead per US gallon, maximum 1.12 grams/litre. 100LL "low lead" was designed to replace avgas 100/130.
* Avgas 100LL contains a maximum of 2 grams of lead per US gallon, or maximum 0.56 grams/litre, and is the most commonly available and used aviation gasoline.
In the past other grades were also available, particularly for military use, such as avgas 115/145. Note that the octanes of avgas cannot be directly compared to those of mogas, as a different test engine and method is used to determine the octane. The first (lower) number is the lean mixture rating, the second (higher) number is the rich rating. For mogas, the octane rating is typically expressed as an anti-knock index, which is the average of the octane rating based on the research and motor test method ((R+M)/2).
To aid pilots in identifying the fuel in their aircraft, dyes are added to the fuel. 80/87 is red, 100/130 is green, and 100LL is blue, while jet fuel, JET A1, is clear or straw, being undyed.
There is the quote from that site. Ok, Avgas is not rated the same as a cars. It has octane added by the use of lead. So, how much knock resistance does this have in a car. My buddy was running it in his 300zx at 24psi of boost with no knock. I take it that it is higher octane than your normal pump gas, or at least has more knock resistance.
So, whats the deal?
* Avgas 80/87 has the lowest lead content at a maximum of 0.5 grams lead per US gallon, and is only used in very low compression ratio engines.
* Avgas 100/130 is a higher octane grade aviation gasoline, containing a maximum of 4 grams of lead per US gallon, maximum 1.12 grams/litre. 100LL "low lead" was designed to replace avgas 100/130.
* Avgas 100LL contains a maximum of 2 grams of lead per US gallon, or maximum 0.56 grams/litre, and is the most commonly available and used aviation gasoline.
In the past other grades were also available, particularly for military use, such as avgas 115/145. Note that the octanes of avgas cannot be directly compared to those of mogas, as a different test engine and method is used to determine the octane. The first (lower) number is the lean mixture rating, the second (higher) number is the rich rating. For mogas, the octane rating is typically expressed as an anti-knock index, which is the average of the octane rating based on the research and motor test method ((R+M)/2).
To aid pilots in identifying the fuel in their aircraft, dyes are added to the fuel. 80/87 is red, 100/130 is green, and 100LL is blue, while jet fuel, JET A1, is clear or straw, being undyed.
There is the quote from that site. Ok, Avgas is not rated the same as a cars. It has octane added by the use of lead. So, how much knock resistance does this have in a car. My buddy was running it in his 300zx at 24psi of boost with no knock. I take it that it is higher octane than your normal pump gas, or at least has more knock resistance.
So, whats the deal?
suprasport91 said:
Octane is not a thing at all. It is a term given to fuel to measure its resistance to combustion. And yes water does have a octane rating, it is listed as infinity. Many gasoline companies have unleaded race fuel for cars with 02 sensors and cats, not just VP. Everyone seams to think that c16 is the only unleaded race fuel there is, but VP is really on the expensive side. I used to be able to buy Sunoco 110 unleaded by the 55 gallon drum for 4.25 per gallon delivered to my door. Besides, if you don't like the smell of race gas, then buy some sented aditive to make your exhaust smell like cinnimon.
It's just a number it isn't an actual "thing" LPG I use is rated at 104 octane but has NOTHING in common with 104 octane Petrol.suprasport91 said:
They use a little one cylinder motor and run a fuel in it increasing it's compression until it knocks and this is that fuels "Octane"
IJ. said:
ummmmm
Octane is part of the n-tane famile (heptane, hexane, pentane etc.) and more specifically octane is C8H18.
Octane and more specifically Isooctane is the "100" point while n-heptane is the ZERO point (hence the indy cars running toluene as a fuel cut the toluene down with n-heptane to reach the octane limit as prescribed by the race organization).
now with that said the use of octane in the fuel industry has to do with how the fuel burns compared to Isooctane. Does it have Isooctane? Perhaps or no. But a relationship can be established with burn rate.
IJ. said:LOL you know what I meant!
well of course because geniuses think alike
This is for the other folks