(Just a quick one!) High octane fuel?

[Fabian]

F1 fuel is somewhere between 95-102 (RON), but the F1 regulations would give guidelines as to what the maximum concentrations of volitile aromatics must not be exceeded.

Octane rating is calculated by the following formula: (R+M)/2. One value is the research octane number (RON), which is determined with a test engine running at a low speed of 600 rpm. The other value is the motor octane number (MON), which is determined with a test engine running at a higher speed of 900 rpm. If, for example, a gasoline has an RON of 98 and a MON of 90, then the posted octane number would be the average of the two values or 94.


But the details are below:

All fuel must comply with strict requirements and prior to each race the teams must supply the FIA with two separate five-litre samples for analysis and approval. Additional samples can then be taken during the event to ensure that there is no discrepancy between the fuel being used and that previously supplied in the samples.
The only fuel permitted is petrol having the following characteristics: Property Units Min Max Test Method
RON 95.0 102.0 ASTM D 2699-86
MON 85.0 ASTM D 2700-86
Oxygen %m/m 2.7 Elemental Analysis
Nitrogen mg/kg 500 ASTM D 4629
Benzene %v/v 1.0 EN 238
RVP hPa 450 600 ASTM D 323
Lead g/l 0.005 ASTM D 3237
Density at 15°C kg/m³ 720.0 775.0 ASTM D 4052
Oxidation stability minutes 360 ASTM D 525
Existent gum mg/100ml 5.0 EN 26246
Sulphur mg/kg 10 ASTM D 5453
Copper corrosion rating C1 ISO 2160
Electrical Conductivity pS/m 200 ASTM D 2624


Distillation characteristics: At E70°C %v/v 20.0 48.0 ISO 3405
At E100°C %v/v 46.0 71.0 ISO 3405
At E150°C %v/v 75.0 ISO 3405
Final Boiling Point °C 210 ISO 3405
Residue %v/v 2.0 ISO 3405
The fuel will be accepted or rejected according to ASTM D 3244 with a confidence limit of 95%

 

[kerf]

Wow, I am impressed.

 

[Gh0stRider]

Wow, I am impressed.

Yep - nice cut 'n paste. Still didn't answer my question though.......

 

[kerf]

I never have been able to master that copy & paste thing. Spunky said he would teach me but he never did.

 

[Hajuu]

You are speaking for yourself. You know absolutely nothing about the skill level and the fabrication abilities of other members of this forum. It would also seem you have a limited knowledge of the forum itself, although it's right in front of you. Son, arrogance won't expand your limited knowledge base, some people are still made from the old growth stock.

I never mentioned that you COULDN'T do it.. But are you?

If not, show some respect for the steamy old guy. Sheesh!

 

[Fabian]

Although this appears contradictory, it's applicable for a racing fuel without EPA vapour standards.

Info below from Sunoco:

The burn rate of a fuel is a measurement of the time required for complete combustion of the air/fuel mixture. The notion that octane ratings affect the burn rate of fuel is about 180-degrees from reality; burn rate is a function of several variables, and the two are completely independent, although there is generally a correlation between octane ratings and burn rates.

To give you a good example of this, we contacted Jim Wurth from Sunoco Race Fuels. He explains, "A perfect example is Sunoco Maximal, which is our fastest burning fuel, and coincidentally one of Sunoco's highest octane fuels at 116 (R+M) / 2. A lot of Pro Stock teams rely on Maximal for those sub-seven second runs. When they are turning 9,000 rpm or more, the fuel has to burn pretty quickly to achieve complete combustion".


However,
High octance pump grade fuel is formulated to produce smooth power and minimise vapour emissions.

You can have a scenario of a high octance fuel with a fast flame speed but it won't have the calorific value of a fuel with lower aromatics; requiring more fuel to be consumed to produce a given power level.
An example of this methanol where it has half the calorific value of petrol and a more extreme example is nitromethane where you require 6 times greater fuel quantity than petrol to make 50% more power.
Nitromethane is a good example of how a fuel with an octane rating of approx 60 (although nitromethane isn't an octane fuel) is not useful in turning high rpms.
There is no point going much over 8000 rpm and the engine won't make any substantial gains.

In the world that the average motorist is exposed to at the pertol pump, a higher octane fuel is a slower and more even burning fuel that complies with EPA controls and has the engine operating in a smoother manner

Fabian

 

[kerf]

Although this appears contradictory, it's applicable for a racing fuel without EPA vapour standards.

Info below from Sunoco:

The burn rate of a fuel is a measurement of the time required for complete combustion of the air/fuel mixture. The notion that octane ratings affect the burn rate of fuel is about 180-degrees from reality; burn rate is a function of several variables, and the two are completely independent, although there is generally a correlation between octane ratings and burn rates.

To give you a good example of this, we contacted Jim Wurth from Sunoco Race Fuels. He explains, "A perfect example is Sunoco Maximal, which is our fastest burning fuel, and coincidentally one of Sunoco's highest octane fuels at 116 (R+M) / 2. A lot of Pro Stock teams rely on Maximal for those sub-seven second runs. When they are turning 9,000 rpm or more, the fuel has to burn pretty quickly to achieve complete combustion".


However,
High octance pump grade fuel is formulated to produce smooth power and minimise vapour emissions.

You can have a scenario of a high octance fuel with a fast flame speed but it won't have the calorific value of a fuel with lower aromatics; requiring more fuel to be consumed to produce a given power level.
An example of this methanol where it has half the calorific value of petrol and a more extreme example is nitromethane where you require 6 times greater fuel quantity than petrol to make 50% more power.
Nitromethane is a good example of how a fuel with an octane rating of approx 60 (although nitromethane isn't an octane fuel) is not useful in turning high rpms.
There is no point going much over 8000 rpm and the engine won't make any substantial gains.

In the world that the average motorist is exposed to at the pertol pump, a higher octane fuel is a slower and more even burning fuel that complies with EPA controls and has the engine operating in a smoother manner

Fabian

And this has what to do with a small utility engine on a bicycle?

 

[Gh0stRider]

Looks like his latest cut 'n paste contradicts his point that high octane fuel burns slower and will give more low-midrange power.

.....If however, you're more interested in engine life and stronger bottom and midrange power, premium fuel will be an advantage, having a slower and longer burn time.....


Fabian

 

[Fabian]

That's correct.

Pump grade fuel is designed to give smooth performance, by maintaining maximum cylinder pressure over a longer period, providing more controlled flame front propagation and a longer burn time.

This is most noticeable by the way an engine that does not normally ping, yet does ping under wide open throttle at low revs. If you graph ignition systems, you'll find that ignition advance is reduced at less than a linear rate at wide open throttle and low rpm, then the advance curve is brought back to where it needs to be to keep pace with the correct combustion process, once out of this detonation zone.
Switching, in such an instance, to premium grade fuel will reduce the pinging or stop it completely.

Fabian

 

[kerf]

The only issue anyone will notice on their bike will be detonation. These are not high tech engines and any fuel that meets the basic requirements will work just fine. If you believe running premium will bring some type of "magic" into your life, then that's just what you need to do.

I no longer believe in magic, been that way since 1955 when I found out the tooth fairy was a scam.