Alcohol vs gasoline

Meat Wad

Super Anarchist
we used to put some stove alcohol in our tanks to evaporate any moisture in the gas tank. Engines ran fine
we usually add Startron fuel additive, when we gas up an outboard boat, especially 2-stokes.

Alcohol does not REMOVE any water, it holds it in suspension ( small particulates) in the fuel so it can flow thru the system & burn
Sorry for not knowing the chemistry. This was in the 70's racing to Mexico. Stove alcohol was a savior from the PMEX gas.

 

billy backstay

Backstay, never bought a suit, never went to Vegas
Sorry for not knowing the chemistry. This was in the 70's racing to Mexico. Stove alcohol was a savior from the PMEX gas.


Thank God there were no ubiquitous mobile phones with w/cameras, etc, to permanently record all the shit we did in the '70s, and 80's!!!!!   :blink: :huh:

I share as little as possible on the internet, and I never respond to ANY surveys from every retailer that ever purchased from, including all of my Medical Doctors. 

My Facebook page is viewed by me only 2 or 3 times a year, and I never post anything.

BIG BROTHER IS WATCHING US ALL..  And recording and sharing all available date...

 
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billsreef

Anarchist
871
467
Miami
If engines can run on pure alcohol better than gasoline, then why does a little ethanol added fuck up many outboard and other motors???
Alcohol in the gasoline leads to several problems, especially in boats that spend time sitting in between use. The alcohol degrades rubber, so fuel lines, fuel pump diaphragms, carb seals and floats, needle valves etc. There are now USCG approved alcohol resistant fuel hoses, and there updated components that can replace those parts in the fuel system that degrade, but mostly for newer engines. The alcohol is also more volatile, so the fuel rapidly drops octane and energy just from sitting. This is more noticeable in older engines that can be cranky about the quality of the gas. I've dealt with some old engines that won't run on gas that has been sitting more than a week as a result of that issue. One of the problems is that the high octane of ethanol allows the blender to use a lower quality, lower octane gasoline that doesn't burn as clean and of course becomes low octane crap after sitting. Rebuild more than few outboards with badly carboned pistons and rings from that crap gas/alcohol blend. The water thing mentioned earlier, yeah, that's a real problem in a boat with a properly vented tank sitting in a high humidity environment. Not only can you end up with a substantial load of water that has phase separated, that water sitting in things like fuel filters, tanks, carburetor bowels, vapor separator tanks (in modern fuel injected outboards) can cause corrosion. Real fun to clean all that out. Modern vapor separator tanks aren't all that different from an old two stroke carb when comes to cleaning all those little passages from the creeping crud.

With the US insistence on using corn instead of a more practical crop for alcohol production, it's not even an energy efficient choice.

 

Lark

Supper Anarchist
9,671
1,800
Ohio
Alcohol in the gasoline leads to several problems, especially in boats that spend time sitting in between use. The alcohol degrades rubber, so fuel lines, fuel pump diaphragms, carb seals and floats, needle valves etc. There are now USCG approved alcohol resistant fuel hoses, and there updated components that can replace those parts in the fuel system that degrade, but mostly for newer engines. The alcohol is also more volatile, so the fuel rapidly drops octane and energy just from sitting. This is more noticeable in older engines that can be cranky about the quality of the gas. I've dealt with some old engines that won't run on gas that has been sitting more than a week as a result of that issue. One of the problems is that the high octane of ethanol allows the blender to use a lower quality, lower octane gasoline that doesn't burn as clean and of course becomes low octane crap after sitting. Rebuild more than few outboards with badly carboned pistons and rings from that crap gas/alcohol blend. The water thing mentioned earlier, yeah, that's a real problem in a boat with a properly vented tank sitting in a high humidity environment. Not only can you end up with a substantial load of water that has phase separated, that water sitting in things like fuel filters, tanks, carburetor bowels, vapor separator tanks (in modern fuel injected outboards) can cause corrosion. Real fun to clean all that out. Modern vapor separator tanks aren't all that different from an old two stroke carb when comes to cleaning all those little passages from the creeping crud.

With the US insistence on using corn instead of a more practical crop for alcohol production, it's not even an energy efficient choice.
Interesting observation on older engines.   My personal experience was the opposite.   I assumed the old jets were just too big to plug with corrosion.  The ancient Evinrude sucks gas like a porn star and the Tohatsu has the appetite of a married woman who was faithful  (If it started at all, it wouldn't drain the tank very fast).   

 

BeSafe

Super Anarchist
8,121
1,363
Of the hydrocarbons, Ethanol tends to unzip stupid easy.  That can lead to carbon build up in places that are near but not in the combustion zone itself for engines that aren't designed to burn it.   Its azeotrope with water also makes it quirky if you're trying to use 'only' ethanol.  Unless you're doing chemistry, very few people use 'pure ethanol' because it's both unnecessary and expensive to purify.  Once you get up past the diesels/kerosenes, you start running into a high fraction of benzene ring containing compounds that don't like to come apart at all - leaving behind that mix we like to call tar, residue, 'wet stack' or whatever.  Its all the same stuff - a hodge-podge of partially combusted goo. 

To much detail but for any incomplete combustion, the answer is 'it depends' :) and there is no magic engine design for all fuels.  BTW:  Octane in gas refers to the tendency to pre-ignite due to compression.  That's also chemistry dependent.

As a 'fuel', the problem with ethanol is cost, related mostly to water.  The yeast that make ethanol from sugar toxify their environment around 8-12% depending on the yeast so if you're doing plant ->sugar->ethanol then you've got AT LEAST 84% water to get rid of at the end.

A gallon of ethanol has 77000 BTU of energy content.  A gallon of ethanol made by fermentation begins its its life with 6 gallons of water attached.  The energy required to heat and boil off 6 gallons of water is about 63000 BTU.

So yes, for every 77000 BTUs of energy, somewhere along the line, someone has paid 63000 BTUs to get the water out of it.  That's not including any energy spent getting the plant in the first place - that's the EROEI at END cleanup phase.  Unless it's synthesized directly from fossil.   Then Ethanol is just wasteful, not criminally wasteful.

Yes, ethanol is that bad.

You want to destroy the earth, just mandate more ethanol.

 

El Borracho

Verified User
6,839
2,797
Pacific Rim
Alcohol in the gasoline leads …
I think the alcohol rants are political. Of my dozen ancient IC engines around here I have no trouble with the cheapest California ethanol blend regular gasoline in town.

Just this morning I split some wood for the first time in over two years. 30 year old B&S engine. Checked the oil, cleaned out the leaves, topped up with year-old fuel, pulled the rope 3 times and split wood. No burst rubber hoses. Ran perfect. Has a flat tire, though. Always the same with every engine here. Sometimes a carb bowl gets cleaned, but not often.

Engine mojo?

 

BeSafe

Super Anarchist
8,121
1,363
Then Ethanol is just wasteful, not criminally wasteful.

Yes, ethanol is that bad.

You want to destroy the earth, just mandate more ethanol.
<EDIT>  There is a scenario where ethanol make sense energetically - if you add the water/ethanol mix to a coal-slurry plant, it improves the coal combustion and removes most of the energy penalty.  So there is that.  But it's not worth the materials handling issues.

 
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Pertinacious Tom

Importunate Member
62,906
2,018
Punta Gorda FL
The water thing mentioned earlier, yeah, that's a real problem in a boat with a properly vented tank sitting in a high humidity environment. Not only can you end up with a substantial load of water that has phase separated, that water sitting in things like fuel filters, tanks, carburetor bowels, vapor separator tanks (in modern fuel injected outboards) can cause corrosion.
It's not really water. It's goo. Doesn't flow like water but does corrode things like salt water.

The dealership where I worked was a Tohatsu sales/service center prior to ethanol. It went like this: sell people a new Sun Cat with a new Tohatsu. People in this area with that money are snowbirds, so they leave. And leave the vented fuel tank in the garage for the FL summer. They come back down, put the boat in the water, fire it up, go for a while until the goo arrives at the carb, then stop. They come to the shop complaining that the brand new engine died. We take it apart, find the goo and corrosion, and have to explain to them that it's their fault for using shitty gas and Tohatsu will not cover it under warranty. This conversation never went well. We went out of the service business and just sold 'em.

 

Lark

Supper Anarchist
9,671
1,800
Ohio
I think the alcohol rants are political. Of my dozen ancient IC engines around here I have no trouble with the cheapest California ethanol blend regular gasoline in town.

Just this morning I split some wood for the first time in over two years. 30 year old B&S engine. Checked the oil, cleaned out the leaves, topped up with year-old fuel, pulled the rope 3 times and split wood. No burst rubber hoses. Ran perfect. Has a flat tire, though. Always the same with every engine here. Sometimes a carb bowl gets cleaned, but not often.

Engine mojo?
Do you live in a desert?    It rains in Ohio,   I have three small engines, two new and one a 1982 outboard,    Only the 1982 has its original carb.    The 6 year old Tohatsu has had two carbs, four jets in six years, despite running the float empty every use, sea foam, stabilizers, etc.   




 
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billsreef

Anarchist
871
467
Miami
It's not really water. It's goo. Doesn't flow like water but does corrode things like salt water.
Up in the Northeast we would get enough water to actually settle out in a proper water layer. That goo in the system was always fun (not). The result of the volatiles evaporating and leaving a combination of water, alcohol and varnish. If it sat long enough to fully dry, then it took a couple of days soaking in the Zep. My wife hated when I rebuilt carbs, couldn't stand the smell of Zep. Made me take my clothes off on the porch and leave them outside when I came home from the shop. 

 

El Borracho

Verified User
6,839
2,797
Pacific Rim
Do you live in a desert?    It rains in Ohio,   I have three small engines, two new and one a 1982 outboard,    Only the 1982 has its original carb.    The 6 year old Tohatsu has had two carbs, four jets in six years, despite running the float empty every use, sea foam, stabilizers, etc.   
Maybe. It is dry here relative to Ohio. I recall replacing one carb over the years. And cleaning the Honda generator carb bowl a couple of times (in decades) bcuz the entire tank will evaporate thru it in the hot months when the shutoff cock is neglected by the drunk that runs this place. 

 

Steam Flyer

Sophisticated Yet Humble
45,586
10,275
Eastern NC
Don't forget that - in a moment in history were food shortages are predicted - it also means you've converting food prodicing land to energy produicung land. Might not be a good idea
Matter of priorities.

We need energy to produce the food in the first place, and certainly need energy to distribute the food.

Now, if you get down to the specific case of burning gasoline (in tractors etc) to produce alcohol for fuel, yeah that's kinda dumb.

- DSK

 

BeSafe

Super Anarchist
8,121
1,363
It's not really water. It's goo. Doesn't flow like water but does corrode things like salt water.
It's often referred to as pyrolysis oil but I call it 'goo' too :)

" Pyrolysis oil is a kind of tar and normally contains levels of oxygen too high to be considered a pure hydrocarbon. This high oxygen content results in non-volatility, corrosiveness, immiscibility with fossil fuels, thermal instability, and a tendency to polymerize when exposed to air.[1] As such, it is distinctly different from petroleum products."

Its not a single compound but a mix of all kinds of partially-oxidized and cross-linked stuff. 

 
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mikewof

mikewof
45,868
1,246
Do you live in a desert?    It rains in Ohio,   I have three small engines, two new and one a 1982 outboard,    Only the 1982 has its original carb.    The 6 year old Tohatsu has had two carbs, four jets in six years, despite running the float empty every use, sea foam, stabilizers, etc.  
For the small displacement engines, may I introduce you to The Word and Faith of our Holy Savior? So expensive, so worth it. I no longer use stabilizers, foamers, cleaners, and other than the chainsaw and the weedwacker, I don't even usually have to have the carbs empty anymore ...

Screen Shot 2022-04-16 at 10.22.00 PM.png

 

mikewof

mikewof
45,868
1,246
Matter of priorities.

We need energy to produce the food in the first place, and certainly need energy to distribute the food.

Now, if you get down to the specific case of burning gasoline (in tractors etc) to produce alcohol for fuel, yeah that's kinda dumb.

- DSK
Energy used to be a big issue with food production, "how much energy does it take to make food, how much food does it take to make energy?" That was the era of feeding oxen and ranch hands and such.

Then the world shifted after WWII, and mechanization in agriculture, to where water was needed to make energy, the big questions became "how much water does it take to make energy and how much energy does it take to make water?" The latter part of that question has become more important with water shortages, water transport and desalination. But for the most part, agriculture still had enough water, even in places like California and Arizona, where there rightfully wasn't enough water to sustain the kind of production we had.

And now, energy is gets cheaper, the big questions becomes, "how much water does it take to make food and how much water does it take to make energy?" The argument with biofuels is less of an issue, we gradually move away from combustion anyway. But we still need lots of water to run hydropower, to run steam turbines for coal, natural gas and legacy nuclear, and then we need that water for agriculture. We have to decide how we are going to spend the water that we have. A huge chunk of the planet has limited water, unlike those who grow cows and grain near the Great Lakes and few other blessed spots.

We will continue to flip between these issues, part of the "Food-Energy-Water Nexus" ... link

null.png


 
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Raz'r

Super Anarchist
63,141
5,852
De Nile
Matter of priorities.

We need energy to produce the food in the first place, and certainly need energy to distribute the food.

Now, if you get down to the specific case of burning gasoline (in tractors etc) to produce alcohol for fuel, yeah that's kinda dumb.

- DSK
It's not just fuel in the tractors, it's oil-based fertilizers for the fields, etc etc.  The science is pretty clear BTUs in > BTUs out...

 

Pertinacious Tom

Importunate Member
62,906
2,018
Punta Gorda FL
It's often referred to as pyrolysis oil but I call it 'goo' too :)

" Pyrolysis oil is a kind of tar and normally contains levels of oxygen too high to be considered a pure hydrocarbon. This high oxygen content results in non-volatility, corrosiveness, immiscibility with fossil fuels, thermal instability, and a tendency to polymerize when exposed to air.[1] As such, it is distinctly different from petroleum products."

Its not a single compound but a mix of all kinds of partially-oxidized and cross-linked stuff. 
Thanks. I'll keep calling it goo. But Immiscible Tom seems like it might be a good screen name.

Oxygen is weird stuff. Too much of it to burn? But oxidizing is what burning IS. So is corroding and I know goo is good at that.

 

kent_island_sailor

Super Anarchist
27,701
5,544
Kent Island!
On 4/16/2022 at 7:46 AM, Lark said:

Do you live in a desert?    It rains in Ohio,   I have three small engines, two new and one a 1982 outboard,    Only the 1982 has its original carb.    The 6 year old Tohatsu has had two carbs, four jets in six years, despite running the float empty every use, sea foam, stabilizers, etc.   


I have taken to buying avgas for my lawn equipment. It is designed for intermittent use and has NO alcohol. Also it is WAY cheaper than the special gas in quart cans at the store.

 

warbird

Super Anarchist
16,688
1,437
lake michigan
Of the hydrocarbons, Ethanol tends to unzip stupid easy.  That can lead to carbon build up in places that are near but not in the combustion zone itself for engines that aren't designed to burn it.   Its azeotrope with water also makes it quirky if you're trying to use 'only' ethanol.  Unless you're doing chemistry, very few people use 'pure ethanol' because it's both unnecessary and expensive to purify.  Once you get up past the diesels/kerosenes, you start running into a high fraction of benzene ring containing compounds that don't like to come apart at all - leaving behind that mix we like to call tar, residue, 'wet stack' or whatever.  Its all the same stuff - a hodge-podge of partially combusted goo. 

To much detail but for any incomplete combustion, the answer is 'it depends' :) and there is no magic engine design for all fuels.  BTW:  Octane in gas refers to the tendency to pre-ignite due to compression.  That's also chemistry dependent.

As a 'fuel', the problem with ethanol is cost, related mostly to water.  The yeast that make ethanol from sugar toxify their environment around 8-12% depending on the yeast so if you're doing plant ->sugar->ethanol then you've got AT LEAST 84% water to get rid of at the end.

A gallon of ethanol has 77000 BTU of energy content.  A gallon of ethanol made by fermentation begins its its life with 6 gallons of water attached.  The energy required to heat and boil off 6 gallons of water is about 63000 BTU.

So yes, for every 77000 BTUs of energy, somewhere along the line, someone has paid 63000 BTUs to get the water out of it.  That's not including any energy spent getting the plant in the first place - that's the EROEI at END cleanup phase.  Unless it's synthesized directly from fossil.   Then Ethanol is just wasteful, not criminally wasteful.

Yes, ethanol is that bad.

You want to destroy the earth, just mandate more ethanol.
That is pure GOLD right there...

 

Foreverslow

Super Anarchist
Lower compression? Heavier oil? I have a late-model vehicle that uses zero-weight motor oil, very light viscosity, I imagine that would be more sensitive than an older engine that uses 40-weight. Also, newer engines tend to run leaner and cleaner anyway, maybe the seals are sensitive to it?

It's not an issue for me, I won't use that shit in any of my small engines, especially the two-strokes. My chainsaw and small engines get premix TruFuel. It's about $18 per gallon, but well worth the price, my engines don't die from that ethanol bullshit.
may want to rethink that.




If you follow her channel, you know this lady is a great small engine mechanic.
and by telling people about this brand, she hurts her own business for repairing various units.
 

mikewof

mikewof
45,868
1,246
may want to rethink that.




If you follow her channel, you know this lady is a great small engine mechanic.
and by telling people about this brand, she hurts her own business for repairing various units.


This isn't rocket surgery. If the octane is too high or too low for the engine then it will foul/carbon or detonate/overrun. If I had an old war horse like her Stihl, I wouldn't use the 92 octane of the Trufuel, it was built for probably closer to 86 octane. And to my memory of those older engines, they have rubber seals that are not as sensitive to the ethanol anyway.

Trufuel is made for the newer engines with synthetic seals, neoprene flaps and such, the kind of materials that get eaten alive by ethanol. My small engines run better on it than gas from the pump, but they are newer engines and all two strokes. (I run my two-stroke snowmobile with gas pump gas, as well as two dirtbikes, both four-strokes.) So far, the Trufuel has given me plenty of power, and I have not had to rebuild any of the small engines. I do have to rebuild the Polaris sled and the Honda XR-500, but that mostly has to do with both of those machines being run like raped apes.

Also, older engines were designed for somewhat lower octanes because of the way gasoline was stored in vented tanks, until the more recent unvented tanks that @Pertinacious Tom hates, he had a whole thread on his Normy-based disdain for unvented tanks. With the vented tanks, the more volatile (lower vapor pressure) components of the gasoline boiled off first, which left the higher vapor pressure stuff in the tank, and those older engines were designed to run reasonably well on fuel from a vented tank filled at the beginning of the summer. But obviously, new untented tanks and those unvented Trufuel bottles keep roughly the same volatile ratio after months of storage than as new. (Though there is degradation as they are repeatedly opened and closed, as she noted in her video with absorbing the water.) These newer two-stroke engines are built to a narrower fuel burn because they can be ... fuel tends to stay fresher these days.

I don't know the compression ratio or year of her Stihls in the video, but it is tough to do a side-by-side comparison like that even with engines of similar builds. And that isn't the point anyway ... the enemy of small engines is what ethanol does to the components, and in some states (like mine) getting ethanol free fuel at the pump is nearly impossible, so we use the canned fuel.
 
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