Ethanol vs Methanol, why both?

[David Redszus]

Ethanol blended fuels (Gasahol) have anti-corrosion additives added by the refinery.

So pump "e85" whether that be the 60-70 percent ethanol i usually see.....contains these anti-corrosion additives?

Would there be any benefit to adding additional anti-corrosion additives, and what are they?

Thanks

A wide range of various compounds are used as corrosion inhibitors, including amine salts of alkenyl succinic acids, alkyl orthophosphoric acids, aryl sulfonic acids, Manich amines, etc.

Fuel additive chemistry is a complex area and even refineries rely upon the expertise of outside specialists.
Gasoline additives, at the user level, are motly counter-productive and best left to refineries.

[NewbVetteGuy]

I'm curious about this because I blended a GEM fuel.

40% gasoline (90 AKI, non-ethanol)
12% ethanol
48% methanol

Your magic elixar will have the folowing properties:
Power = 1298 BTU/lb air
Oxygen - 28.15%
Specific G = 0.780
Stoich = 10.09

David, if someone wanted to target a stoich of 9.76:1 (same as E85?) with a GEM mix, what % of Gasoline, Ethanol, and Methanol should they use?

-I came across a confusing chart that implied that there might be multiple mixes possible to match E85's stoich value, but it went over my head on how to actually figure out what blend to use.


Adam

[NewbVetteGuy]

Would there be any benefit to adding additional anti-corrosion additives, and what are they?

Thanks

Exactly! It sure would be nice if some fuel additives company that sells octane booster sold an anti-corrosion additive for a common GEM blend that matched E85...

DIY blending GEM is easy, if you could get a good anti-corrosion additive... (There's loads of them that claim to be for E85; no idea if the same ones will work for a common GEM blend.)
I've made my own "E85" before, but not at a large scale and I didn't feed it to my engine...



Adam

[fabr]

Ethanol blended fuels (Gasahol) have anti-corrosion additives added by the refinery.

So pump "e85" whether that be the 60-70 percent ethanol i usually see.....contains these anti-corrosion additives?

Would there be any benefit to adding additional anti-corrosion additives, and what are they?

Thanks

A wide range of various compounds are used as corrosion inhibitors, including amine salts of alkenyl succinic acids, alkyl orthophosphoric acids, aryl sulfonic acids, Manich amines, etc.

Fuel additive chemistry is a complex area and even refineries rely upon the expertise of outside specialists.
Gasoline additives, at the user level, are motly counter-productive and best left to refineries.

And no additives is why I blend my own e85 from e98 straight from the distiller in MN. 2% denaturant as all "pure" ethanol is to keep it legal for sale and since it is anhydrous it has almost zero water content. Even with shipping and drum costs it is considerably less than 1/2 the cost of race gas. Still have yet to have any corrosion issues. It is when ethanol comes near saturation that bad things happen. Phase separation is ugly for sure. If using either methanol or ethanol storage and fuel systems need to protect it from water being possibly absorbed since it attracts water like a magnet to steel.

[David Redszus]

I'm curious about this because I blended a GEM fuel.

40% gasoline (90 AKI, non-ethanol)
12% ethanol
48% methanol

Your magic elixar will have the folowing properties:
Power = 1298 BTU/lb air
Oxygen - 28.15%
Specific G = 0.780
Stoich = 10.09

David, if someone wanted to target a stoich of 9.76:1 (same as E85?) with a GEM mix, what % of Gasoline, Ethanol, and Methanol should they use?
-I came across a confusing chart that implied that there might be multiple mixes possible to match E85's stoich value, but it went over my head on how to actually figure out what blend to use.
Adam

A blend of 85% ethanol. 15% gasoline would have a stoich value of 9.84 and a RVP of only 2.6. A crap fuel.

There are other possibilities:
35% gasoline, 20% ethanol, 45% methnol would have a stoich of 9.84 and a RVP of 3.5.
45% gasoline, 0% ethanol, 55% methanol would have a stoich of 10.2 and RVP of 4.0. A better fuel.

A low stoich number means that a large amount of fuel must be used, which may not fully evaporate;
and may be difficult to ignite, resulting in mucho carbon deposits.
A low RVP means poor evaporation and poor throttle response.

I would have to see a very hot day to persuade me to run either alcohol; except for use in turbo motors.

In the total scheme of racing budgets, a quality, properly selected, race fuel is cheap and a very good investment
in engine durability and consistency.

[RDY4WAR]

My main reason for using E85 and GEM fuel is predictability in a bracket car. Carrying it's own oxygen and lots of it, it's less effected by changes in ambient conditions. Also with the cooling effect, it's easier to keep starting line coolant temp consistent. That's why I use it.

I'm also looking for the best ET out of this mild combo when I'm not bracket racing it. I have a fascination with trying to go as fast as possible with as a few modifications as possible and tweaking fine details like windage, viscous oil losses, pumping losses, rolling resistance, brake drag, etc... and of course the fuel.

[KnightEngines]

Your magic elixar will have the folowing properties:
Power = 1298 BTU/lb air
Oxygen - 28.15%
Specific G = 0.780
Stoich = 10.09

David, if someone wanted to target a stoich of 9.76:1 (same as E85?) with a GEM mix, what % of Gasoline, Ethanol, and Methanol should they use?
-I came across a confusing chart that implied that there might be multiple mixes possible to match E85's stoich value, but it went over my head on how to actually figure out what blend to use.
Adam

A blend of 85% ethanol. 15% gasoline would have a stoich value of 9.84 and a RVP of only 2.6. A crap fuel.

There are other possibilities:
35% gasoline, 20% ethanol, 45% methnol would have a stoich of 9.84 and a RVP of 3.5.
45% gasoline, 0% ethanol, 55% methanol would have a stoich of 10.2 and RVP of 4.0. A better fuel.

A low stoich number means that a large amount of fuel must be used, which may not fully evaporate;
and may be difficult to ignite, resulting in mucho carbon deposits.
A low RVP means poor evaporation and poor throttle response.

I would have to see a very hot day to persuade me to run either alcohol; except for use in turbo motors.

In the total scheme of racing budgets, a quality, properly selected, race fuel is cheap and a very good investment
in engine durability and consistency.

I disagree, I have personally seen pump swill e85 make 28hp more than VP109 on a 600hp small block.
At less than 1/4 the cost.
If you have a consistant source of e85 it's a hard to beat race fuel.
Equal of all but the big $ race fuels & only a tad behind meth with less of the downsides.

Then you can step up to something like C85, still 1/2 the cost of Q16 but it'll beat it in TQ & equal it in peak power.
Around 15hp better than e85 on a 650hp small block with 13.5:1 comp.

[RDY4WAR]

How much of a difference is there with port EFI vs a carb? Say we take a SBC with a single plane intake and an appropriately sized carburetor and then switch the carb for a throttle body of equal flow capacity with injectors installed in the runners near the heads for port EFI. Same E85 and GEM fuels for both.

Carb gives the fuel more time in the intake tract to cool the intake charge, though you mentioned some of this is lost to cooling the aluminum manifold.

The port EFI wouldn't likely cool the manifold as much though you lose the time to cool the intake charge. How much would differences in fuel atomization play a factor?

With a higher percentage of the intake charge being fuel with E85 and GEM, displacing more of the ambient air, what impact does this have on port design and fuel particle flow path into the cylinders? How does it impact quench/squish parameters? (if at all)

David, you mentioned a fuel that's 45% gasoline and 55% methanol. It's my understanding that gasoline and methanol are not miscible, which is why a GEM fuel has a small percentage of ethanol to act as a binder. Is this incorrect? Are there additives that can be used instead of adding ethanol, such as trimethylolpropane monooleate or triacrylate that can act multi-functionally as an emulsifier, corrosion inhibitor, and stabilizer? I know they work in this regard with oils/lubricants, but not sure if they'd serve the same function in fuel.

[KnightEngines]

How much of a difference is there with port EFI vs a carb? Say we take a SBC with a single plane intake and an appropriately sized carburetor and then switch the carb for a throttle body of equal flow capacity with injectors installed in the runners near the heads for port EFI. Same E85 and GEM fuels for both.

Carb gives the fuel more time in the intake tract to cool the intake charge, though you mentioned some of this is lost to cooling the aluminum manifold.

The port EFI wouldn't likely cool the manifold as much though you lose the time to cool the intake charge. How much would differences in fuel atomization play a factor?

With a higher percentage of the intake charge being fuel with E85 and GEM, displacing more of the ambient air, what impact does this have on port design and fuel particle flow path into the cylinders? How does it impact quench/squish parameters? (if at all)

David, you mentioned a fuel that's 45% gasoline and 55% methanol. It's my understanding that gasoline and methanol are not miscible, which is why a GEM fuel has a small percentage of ethanol to act as a binder. Is this incorrect? Are there additives that can be used instead of adding ethanol, such as trimethylolpropane monooleate or triacrylate that can act multi-functionally as an emulsifier, corrosion inhibitor, and stabilizer? I know they work in this regard with oils/lubricants, but not sure if they'd serve the same function in fuel.

Port efi vs carb - of the 2 I've seen results for 1 was a wash, the other the carb beat it by somewhere around 10hp & 15lb, low 500's hp engine.
The carb definitely has the charge cooling advantage.
Manifold cooling is a by-product of charge cooling, if the manifold is cold then the charge is cold.
I regularly see condensation running down carb e85 intakes on humid days on the dyno.

[hoffman900]

Neither alcohol is considered a desireable fuel for transportation and would not be used except
for the role of politics.

Partly. Ethanol is seen as a replacement to MTBE, which is renders water un potable around 20-40ppb, and even at concentrations below that, has a terrible taste. It also travels faster (ie: further) than BTEX that composes gasoline and doesn't break down as quickly in the environment. When you observe A LOT of gas stations built before the 2000s have leaked at some point, it's an issue. That said, ethanol makes BTEX compounds last longer in the environment. When E10 and other formulas are released into groundwater, the ethanol breaks down first, when that happens the the dissolved oxygen drops, and BTEX breaks down (and is traveling further since groundwater is still moving) more slowly.

But, yeah, Big AG lobby is a thing.

[David Redszus]

Neither alcohol is considered a desireable fuel for transportation and would not be used except
for the role of politics.

Partly. Ethanol is seen as a replacement to MTBE, which is renders water un potable around 20-40ppb, and even at concentrations below that, has a terrible taste. It also travels faster (ie: further) than BTEX that composes gasoline and doesn't break down as quickly in the environment.

But, yeah, Big AG lobby is a thing.

After extension testing, the US military found MTBE to be the superior fuel blending additive.

The best racing fuels once contained MTBE, not alcohols. We still use it for custom race fuel blends.

[hoffman900]

Neither alcohol is considered a desireable fuel for transportation and would not be used except
for the role of politics.

Partly. Ethanol is seen as a replacement to MTBE, which is renders water un potable around 20-40ppb, and even at concentrations below that, has a terrible taste. It also travels faster (ie: further) than BTEX that composes gasoline and doesn't break down as quickly in the environment.

But, yeah, Big AG lobby is a thing.

After extension testing, the US military found MTBE to be the superior fuel blending additive.

The best racing fuels once contained MTBE, not alcohols. We still use it for custom race fuel blends.

You are approaching it from a fuel combustion standpoint and not looking at the big picture. In an engine, I agree. From a remediation standpoint there are a lot of leaking tanks, lines, and spills.

[NewbVetteGuy]

Your magic elixar will have the folowing properties:
Power = 1298 BTU/lb air
Oxygen - 28.15%
Specific G = 0.780
Stoich = 10.09

David, if someone wanted to target a stoich of 9.76:1 (same as E85?) with a GEM mix, what % of Gasoline, Ethanol, and Methanol should they use?
-I came across a confusing chart that implied that there might be multiple mixes possible to match E85's stoich value, but it went over my head on how to actually figure out what blend to use.
Adam

A blend of 85% ethanol. 15% gasoline would have a stoich value of 9.84 and a RVP of only 2.6. A crap fuel.

There are other possibilities:
35% gasoline, 20% ethanol, 45% methnol would have a stoich of 9.84 and a RVP of 3.5.
45% gasoline, 0% ethanol, 55% methanol would have a stoich of 10.2 and RVP of 4.0. A better fuel.

A low stoich number means that a large amount of fuel must be used, which may not fully evaporate;
and may be difficult to ignite, resulting in mucho carbon deposits.
A low RVP means poor evaporation and poor throttle response.

I would have to see a very hot day to persuade me to run either alcohol; except for use in turbo motors.

In the total scheme of racing budgets, a quality, properly selected, race fuel is cheap and a very good investment
in engine durability and consistency.

So most GEM blends with a large % of ethanol and methanol are going to have very low RVPs...

What are the good ways that blenders add more appropriate RVP numbers for an NA engine?

We know winter pump gas gets butane added (RVP = 52 PSI?) -but is that just because it's effective and cheap or is it otherwise useful in the blend?

Volatile aromatics have to be called volatile for a reason... is this one of the big roles that Benzene, Toluene, and Xylene play?


And how much does RVP matter with fine atomizing port injectors, anyway?


Adam

[hoffman900]

How much of a difference is there with port EFI vs a carb? Say we take a SBC with a single plane intake and an appropriately sized carburetor and then switch the carb for a throttle body of equal flow capacity with injectors installed in the runners near the heads for port EFI. Same E85 and GEM fuels for both.

Carb gives the fuel more time in the intake tract to cool the intake charge, though you mentioned some of this is lost to cooling the aluminum manifold.

The port EFI wouldn't likely cool the manifold as much though you lose the time to cool the intake charge. How much would differences in fuel atomization play a factor?

With a higher percentage of the intake charge being fuel with E85 and GEM, displacing more of the ambient air, what impact does this have on port design and fuel particle flow path into the cylinders? How does it impact quench/squish parameters? (if at all)

David, you mentioned a fuel that's 45% gasoline and 55% methanol. It's my understanding that gasoline and methanol are not miscible, which is why a GEM fuel has a small percentage of ethanol to act as a binder. Is this incorrect? Are there additives that can be used instead of adding ethanol, such as trimethylolpropane monooleate or triacrylate that can act multi-functionally as an emulsifier, corrosion inhibitor, and stabilizer? I know they work in this regard with oils/lubricants, but not sure if they'd serve the same function in fuel.

Port efi vs carb - of the 2 I've seen results for 1 was a wash, the other the carb beat it by somewhere around 10hp & 15lb, low 500's hp engine.
The carb definitely has the charge cooling advantage.
Manifold cooling is a by-product of charge cooling, if the manifold is cold then the charge is cold.
I regularly see condensation running down carb e85 intakes on humid days on the dyno.

Only if you are using injectors close to the valve. Most of your Indy Car engines going back to the early 1980s until they went DI injected from the top of the plenum, which is exactly what the Pro Stock builders would do too, if allowed.

Also, with very high injection pressures, the Delta P across the injector to the port is much higher than a carburetor, which is only pressured to atmospheric, and thus there are other cooling gains.

You guys need to step outside the box some here.

[KnightEngines]

How much of a difference is there with port EFI vs a carb? Say we take a SBC with a single plane intake and an appropriately sized carburetor and then switch the carb for a throttle body of equal flow capacity with injectors installed in the runners near the heads for port EFI. Same E85 and GEM fuels for both.

Carb gives the fuel more time in the intake tract to cool the intake charge, though you mentioned some of this is lost to cooling the aluminum manifold.

The port EFI wouldn't likely cool the manifold as much though you lose the time to cool the intake charge. How much would differences in fuel atomization play a factor?

With a higher percentage of the intake charge being fuel with E85 and GEM, displacing more of the ambient air, what impact does this have on port design and fuel particle flow path into the cylinders? How does it impact quench/squish parameters? (if at all)

David, you mentioned a fuel that's 45% gasoline and 55% methanol. It's my understanding that gasoline and methanol are not miscible, which is why a GEM fuel has a small percentage of ethanol to act as a binder. Is this incorrect? Are there additives that can be used instead of adding ethanol, such as trimethylolpropane monooleate or triacrylate that can act multi-functionally as an emulsifier, corrosion inhibitor, and stabilizer? I know they work in this regard with oils/lubricants, but not sure if they'd serve the same function in fuel.

Port efi vs carb - of the 2 I've seen results for 1 was a wash, the other the carb beat it by somewhere around 10hp & 15lb, low 500's hp engine.
The carb definitely has the charge cooling advantage.
Manifold cooling is a by-product of charge cooling, if the manifold is cold then the charge is cold.
I regularly see condensation running down carb e85 intakes on humid days on the dyno.

Only if you are using injectors close to the valve. Most of your Indy Car engines going back to the early 1980s until they went DI injected from the top of the plenum, which is exactly what the Pro Stock builders would do too, if allowed.

Also, with very high injection pressures, the Delta P across the injector to the port is much higher than a carburetor, which is only pressured to atmospheric, and thus there are other cooling gains.

You guys need to step outside the box some here.

With an injection system attainable by the average sportsman racer a carb makes more power pretty much every time.
That's NA engines tho, injection shines with boost.