I dont run premix in my car either so WTF.
Other AVGAS LL100 info for the poorride community (unable to buy C12)
- Thread starter OCD Solutions
- Start date
Philip Clemmons
Owner, P&P Performance
- Location
- Richmond, Va
Haha. Good one.
Half flip95
Formerly pondracer95
- Location
- Lake Havasu City AZ
What will be the net octane of different ratios?
(Gallons, based on the filling of a 5 gallon gas jug)
91 Pump : 100 AV
4 : 1
3 : 1
2 : 1
1 : 1
1 : 2
1 : 3
1 : 4
(Gallons, based on the filling of a 5 gallon gas jug)
91 Pump : 100 AV
4 : 1
3 : 1
2 : 1
1 : 1
1 : 2
1 : 3
1 : 4
- Location
- Grand Rapids
So why do so many complain about the cost of fuel? If u want to play it comes with a cost. If you can't, set up a good Pump gas motor and live with it. A motor that needs 100+ octane, isn't a guarantee to be a strong one.
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Sent from my XT1080 using Tapatalk
This is how I blend race & pump... total octanes/total gallons
Pump dispenses in gallons, cans are marked in gallons
5@91 plus 0 @100 =91.0
4@91 plus 1 @100 =92.8
3@91 plus 2 @100 =94.6
2@91 plus 3 @100 =96.4
1@91 plus 4 @100 =98.2
0@91 plus 5 @100 =100
Last edited:
Half flip95
Formerly pondracer95
- Location
- Lake Havasu City AZ
Thank you.
I would also like to see what kevbo would come up with.
I would also like to see what kevbo would come up with.
It sounds like his formula is an exponential function.
Freakrider
X247
- Location
- Tampa Bay area
From GroupK site :
ABOUT AVIATION FUELS - Aviation gasoline (or "av gas") is blended specifically for use in small aircraft. It's also commonly used by many high performance engine owners because of it's high stated octane rating (usually 100-110) and the relatively low price compared to racing fuel. Unfortunately this fuel is not all it appears to be. Avgas octane is rated on a different scale than gasoline's intended for ground level use. What is 100 octane "av", is not necessarily 100 octane "ground level". Besides this, there is also a big chemical difference. Normal ground level race fuels are made up of gas molecules that have a "light end" and a "heavy end". The light end of the molecule ignites easily and burns quickly with a low temperature flame (as a piece of thin newspaper would burn). The heavy end of the molecule is not so easily ignited, but it burns with a much more intense heat (as an oak log would). This heavy end of the gasoline molecule is responsible for the hotter, more powerful part of the combustion process.
Small aircraft are constructed as very weight conscious vehicles. That's because their somewhat weak engines often have difficulty taking off with any extra weight. To help reduce this weight problem, aviation gasoline's are blended with no heavy molecule end. This makes a gallon of avgas weigh substantially less than a gallon of ground level fuel. Since small plane engines turn very low rpms and produce so little power, the omission of the heavy end is not a horsepower issue. However, for high output pwc racing engines, there is defiantly a compromise in power. This, despite the fact that many pwc owners experience the desirable cooler operating temperatures that avgas offers. In addition, some blends of avgas will quickly separate from some oils used in premix situations. For the above reasons, we do not recommend the ongoing use of 100% avgas, and we will not prepare any "avgas" engine kits.
Despite all this bad news, running avgas (accepting the slight power loss) is usually a better choice than burning down a high output engine on regular pump gas. In this situation, the best choice is usually a 50/50 mix of pump and avgas. That provides "some" heavy molecule ends for the engine.
ABOUT AVIATION FUELS - Aviation gasoline (or "av gas") is blended specifically for use in small aircraft. It's also commonly used by many high performance engine owners because of it's high stated octane rating (usually 100-110) and the relatively low price compared to racing fuel. Unfortunately this fuel is not all it appears to be. Avgas octane is rated on a different scale than gasoline's intended for ground level use. What is 100 octane "av", is not necessarily 100 octane "ground level". Besides this, there is also a big chemical difference. Normal ground level race fuels are made up of gas molecules that have a "light end" and a "heavy end". The light end of the molecule ignites easily and burns quickly with a low temperature flame (as a piece of thin newspaper would burn). The heavy end of the molecule is not so easily ignited, but it burns with a much more intense heat (as an oak log would). This heavy end of the gasoline molecule is responsible for the hotter, more powerful part of the combustion process.
Small aircraft are constructed as very weight conscious vehicles. That's because their somewhat weak engines often have difficulty taking off with any extra weight. To help reduce this weight problem, aviation gasoline's are blended with no heavy molecule end. This makes a gallon of avgas weigh substantially less than a gallon of ground level fuel. Since small plane engines turn very low rpms and produce so little power, the omission of the heavy end is not a horsepower issue. However, for high output pwc racing engines, there is defiantly a compromise in power. This, despite the fact that many pwc owners experience the desirable cooler operating temperatures that avgas offers. In addition, some blends of avgas will quickly separate from some oils used in premix situations. For the above reasons, we do not recommend the ongoing use of 100% avgas, and we will not prepare any "avgas" engine kits.
Despite all this bad news, running avgas (accepting the slight power loss) is usually a better choice than burning down a high output engine on regular pump gas. In this situation, the best choice is usually a 50/50 mix of pump and avgas. That provides "some" heavy molecule ends for the engine.
Quinc
Buy a Superjet
- Location
- California
Is there a particular two stroke oil to mix with 100LL or any to stay away from? I am thinking about running 3 91 : 2 100LL in my SJ for when I want to go WOT for long periods of time.
I am guesstimating the compression to be around 180-190psi.
61x/61x 754cc
Decked
freestyle ported
35cc domes
Enhancer
46mm carb
Coffman pipe
I am guesstimating the compression to be around 180-190psi.
61x/61x 754cc
Decked
freestyle ported
35cc domes
Enhancer
46mm carb
Coffman pipe
Be happy that it cost that much. Do you know how we have sub 4 dollar a gallon gas here in the USA?