Ethanol vs Methanol, why both?

[David Redszus]

Circling back to Butane...

Here's data for Butane that I was able to obtain online.

Stoich AFR = 15.42:1
BTU/lb energy = 21,300
BTU/lb HOV = 165.6

21,300 / 15.42 = 1,381 BTU/lb of air energy

165.6 / 15.42 = 10.7 BTU/lb of air heat of vaporization

Let's take a (purely hypothetical) fuel formula that's (before additives)...

Iso-octane - 54%
n-heptane - 13%
toluene - 25%
cyclohexane - 8%

This combination (if my math is correct) should have the following properties...

- AFR = 14.66
- AKI = 89.39
- HOV = 138.86 BTU/lb, 9.47 BTU/lb of air
- BTU = 18,658 BTU/lb, 1273 BTU/lb of air
- BP = TBD
- RVP = 1.69 psi
- SpG = 0.742

If we add 2% butane...

- AFR = 14.68
- AKI = 89.44
- HOV = 139.39 BTU/lb, 9.50 BTU/lb of air
- BTU = 18,684 BTU/lb, 1,273 BTU/lb of air
- BP = TBD
- RVP = 2.70 psi
- SpG = 0.739

If we add 5% butane...

- AFR = 14.70
- AKI = 89.52
- HOV = 140.20 BTU/lb, 9.54 BTU/lb of air
- BTU = 18,724 BTU/lb, 1,274 BTU/lb of air
- BP = TBD
- RVP = 4.21 psi
- SpG = 0.734

If we add 10% butane...

- AFR = 14.74
- AKI = 89.65
- HOV = 141.53 BTU/lb, 9.60 BTU/lb of air
- BTU = 18,790 BTU/lb, 1,275 BTU/lb of air
- BP = TBD
- RVP = 6.72
- SpG = 0.725

If we add 15% butane...

- AFR = 14.78
- AKI = 89.78
- HOV = 142.87 BTU/lb, 9.67 BTU/lb of air
- BTU = 18,856 BTU/lb, 1,276 BTU/lb of air
- BP = TBD
- RVP = 9.24 psi
- SpG = 0.717

Now let's add 10% ethanol to the 15% butane blend...

- AFR = 14.20
- AKI = 90.75
- HOV = 168.08 BTU/lb, 11.84 BTU/lb of air
- BTU = 18,130 BTU/lb, 1,277 BTU/lb of air
- BP = TBD
- RVP = 8.52 psi
- SpG = 0.724

What if we blended the 15% butane blend with 85% ethanol for E85...

- AFR = 9.88
- AKI = 98.04
- HOV = 357.11 BTU/lb, 36.14 BTU/lb of air
- BTU = 12,682 BTU/lb, 1,284 BTU/lb of air
- BP = TBD
- RVP = 3.09 psi
- SpG = 0.778

What about the 15% butane E10 blend with 60% methanol...

- AFR = 9.56
- AKI = 107.7
- HOV = 351.03 BTU/lb, 36.72 BTU/lb of air
- BTU = 12,303 BTU/lb, 1,287 BTU/lb of air
- BP = TBD
- RVP = 6.11 psi
- SpG = 0.765


I think I may be having a little too much fun with this.

Anyway, what I can't figure out quite yet is how butane stays in solution in any of these and where the IBP and 10% BP will fall. It would seem adding 10-15% butane would be excellent for a naturally aspirated drag racing engine.

Why are you using nHeptane? Dump it immediately. It has a boiling point of 209F and a MON of....zero.
And it has a negative response to TEL; add lead and the MON goes down.

Substitute neoHexane; it has a boiling point of 121F and a MON of 93, has a high RVP and responds positively to TEL.

Dump the cyclohexane; bad news. Replace with cyclopentane.Same story; lower BP, higher RVP, higher MON.

Butane is a gas at normal temperatures (BP 31F). Limited amounts can be put into race gas under pressure and
low temperature. The upper practical limit is typically 4%. As soon as the container cap is opened or exposed to room temps, the butane leaves the room. Not many refineries were capable of adding butane to gasoline from a production perspective. The problem is one of keeping the gas in solution under a variety of operating conditions.

OK, back to the drawing board. Consider some combination of the following:
isooctane
isopentane
neohexane
MTBE
cyclopentane
xylene

Other factors to consider are the speed index and the driveability index. Octane and energy are only part of the program.

A winning race fuel has a fairly wide distillation curve which produces a smoother throttle response across the rpm range.
Limited component fuels do not produce smooth throttle response and must be designed for a specific operating condition.

[RDY4WAR]

Why are you using nHeptane?

Because I knew it would get your attention.

To be blunt, I lost a close friend in a house fire last week. Mixing up components to see outcomes, theorizing formulas, and general chemistry is keeping my mind distracted so I don't think about it.

I thew in n-heptane because I was curious what else would be needed to make octane come out typical for pump fuel. I'm currently reading up on hexane, cyclopentane, and ethylbenzene. I'm curious about 2-methylbutane as well.

[gregsdart]

Outlaw circle track racers often run two sets of injecters,
One set a few inchs up the port from the intake valve, and a smaller set aimed right at the valve in the head itself. From what i know, methanol works best in droplets entering the cylinder. Probably because in evaporated state it will take up to much space? Max power comes with a constant flow system, as methanol will provide power over an extremely wide Afr. Throttle response can be explosive with constant flow. Fuel piles up on the intake valve so lag is almost zero! The first time i left the line in my drag car, it was from idle. Instant mile hi wheelie! Scarred the crap out of me. I have really grown to love constant flow injection. Dirt simple, very easy to tune and maintain.
Blown alky motors run about 50 percent fatter than na motors to suppress detonation at godawful boost levels.

[af2]

Why are you using nHeptane?

Because I knew it would get your attention.

To be blunt, I lost a close friend in a house fire last week. Mixing up components to see outcomes, theorizing formulas, and general chemistry is keeping my mind distracted so I don't think about it.

I thew in n-heptane because I was curious what else would be needed to make octane come out typical for pump fuel. I'm currently reading up on hexane, cyclopentane, and ethylbenzene. I'm curious about 2-methylbutane as well.

Quit reading while you are alive! What the hell!!

[RDY4WAR]

That's fair.

[xxdabroxx]

Last weekend racing in 90+ deg weather our car only lost about 3-5 hundredths running E85 while most of our friends running race gas were about 15-20 hundredths down from the cooler weather. We had no heating issues all weekend, engine temps were never higher that 175F max at the end of the track.

I've only been running E85 for this season but so far no corrosion issues to speak of. We've had the bowls off the car a few times changing jets and only minimal white chalky stuff, nothing compared to what I've found in motorcycle carbs after sitting a while on standard E10 pump gas in CA. We do start the car at least every two weeks to get fresh fuel in the bowls but we don't bother sealing up the vent or anything.

[David Redszus]

I've only been running E85 for this season but so far no corrosion issues to speak of. We've had the bowls off the car a few times changing jets and only minimal white chalky stuff,

That white chalky stuff is corrosion.

[David Redszus]

Quit reading while you are alive! What the hell!!

Those who do not read have no advantage over those who cannot read.

[fabr]

I've only been running E85 for this season but so far no corrosion issues to speak of. We've had the bowls off the car a few times changing jets and only minimal white chalky stuff,

That white chalky stuff is corrosion.

Corrosion due to absorbed water from an open to atmosphere fuel system or pump e10 or e85 that is likely at least partially saturated with water. Sealed from atmospheric moisture absorption will not have any corrosion confirming the ethanol is not the agent causing corrosion. This is not my opinion,it is well documented fact.

[David Redszus]

I've only been running E85 for this season but so far no corrosion issues to speak of. We've had the bowls off the car a few times changing jets and only minimal white chalky stuff,

That white chalky stuff is corrosion.

Corrosion due to absorbed water from an open to atmosphere fuel system or pump e10 or e85 that is likely at least partially saturated with water. Sealed from atmospheric moisture absorption will not have any corrosion confirming the ethanol is not the agent causing corrosion. This is not my opinion,it is well documented fact.

We have tested dozens of drums of E85. Almost all had some percentage of water. And none contained 85% ethanol.

[RDY4WAR]

Just to slam the car in reverse at 70 mph for the sake of doing so...

How much ethanol or acetone would be required to act as a binding agent to make gasoline and methanol miscible when methanol is >50% of the fuel by weight? Could as little as 1-2% ethanol or acetone do it or would you need a good bit more?

This is purely for chemistry knowledge.

[fabr]

That white chalky stuff is corrosion.

Corrosion due to absorbed water from an open to atmosphere fuel system or pump e10 or e85 that is likely at least partially saturated with water. Sealed from atmospheric moisture absorption will not have any corrosion confirming the ethanol is not the agent causing corrosion. This is not my opinion,it is well documented fact.

We have tested dozens of drums of E85. Almost all had some percentage of water. And none contained 85% ethanol.

I buy drums of anhydrous e98 from the distiller and blend to e85 for consistency. It is as dry as is commercially available. Almost zero water content. Corrosion is a non issue. Guys buying pump e10-85 and also having open fuel systems(usually carbed) can/will have issues with corrosion. The ethanol itself is not corrosive. Methanol on the other hand I understand is corrosive by itself?

[xxdabroxx]

I've only been running E85 for this season but so far no corrosion issues to speak of. We've had the bowls off the car a few times changing jets and only minimal white chalky stuff,

That white chalky stuff is corrosion.

But like I said, I've seen much worse on my dirt bike with pump premium 10% ethanol (that's our only option in CA). It was just a tiny bit above the fuel line in the float bowls. Not enough to clog a jet or anything. If you don't run your engine for months I could see it being an issue but if you're like me and can run it once a week or two I think you'll be fine. Overall, at less that 1/4 the cost of average race fuel I'm happy so far.

I don't do any scientific testing but the water in the graduated cylinder deal shows right at 85% E content every time I've bought it. From what I've read CA gives tax breaks to the producers so long as it has at least 85% ethanol content, I've tested from Januaryish to summer and it's been the same every time. I always go to the same station though, nearest one to me.

[fabr]

I have several friends in Nebraska that buy pump e85 and they swear it always tests 85+ year around. I'm envious of their much cheaper then my e85 but I would still buy and blend from E98. I don't want any issues with $35K plus engines. I go through 4-500 gallons a year.

[David Redszus]

I have several friends in Nebraska that buy pump e85 and they swear it always tests 85+ year around. I'm envious of their much cheaper then my e85 but I would still buy and blend from E98. I don't want any issues with $35K plus engines. I go through 4-500 gallons a year.

E85 Fuel (per EPA)
While pure ethanol is rarely used for transportation fuel, there are several ethanolgasoline blends in use today.
E85 is a blend of 85 percent denatured ethanol and 15percent gasoline.

In certain areas, higher percentages of gasoline will be added to
E-85 during the winter to ensure that vehicles are able to start at very cold temperatures.

E85 cannot be used in a conventional, gasoline-only engine. Vehicles must be
specially designed to run on it. The only vehicles currently available to U.S. drivers
are known as flex fuel vehicles (FFVs), because they can run on E85, gasoline, or any
blend of the two. Much like diesel fuel, E85 is available at specially-marked fueling
pumps. Today, over 1,900 fueling stations offer it.

Depending on the geographical area and season, E85 may contain as little as 70% ethanol.
To improve cold weather performance (and fuel economy), additional gasoline is added to
raise the RVP.

Details are contained in ASTM D-4814 and 4815.