Just for fun......E-85 mods to an auger motor?

[bobbymalone]

why does E-85 gum up stuff?

It seems like it would gum up stuff less than long hydrocarbon chains...?

[hydro]

why does E-85 gum up stuff?

It seems like it would gum up stuff less than long hydrocarbon chains...?

Actually, ethanol is a very efficient solvent for gasoline related deposits. That is why the E-15 gasoline causes problems. It dissolves deposits and the particles get stuck in the jetting of the carbs, plugging them up. In the E-85 (85% ethanol) blend, once cleaned out, it would keep the fuel system very clean.

[riffraff]

Riffraff, Yeah, I stay at the Holiday Inn Express a lot, and I like Google, so I must be an expert, eh?

+1 on the Google. When I was in school all they had was that first apple computer thing. It is amazing the information available now.

Nothing more than a backyard mechanic here....had to work on or fix every motor that I ever owned. Remember the snowmobiles of the late 70's??? Ride, fix, ride, fix twice, repeat.

Don't miss those days at all but I did store away a little bit for future reference. Google helps for the rest

[hydro]

Nothing more than a backyard mechanic here....had to work on or fix every motor that I ever owned. Remember the snowmobiles of the late 70's??? Ride, fix, ride, fix twice, repeat.

I do remember those, I had several. I also had a 440cc Rupp snowmobile motor adapted to a go-kart, with tuned pipes that I am sure the neighbors hated. Sometimes I am surprised I survived. Good times.

[hydro]

The original questions from this morning:

1. Exactly what is E-85 and what makes it a good fuel? What is the drawback?

2. What specific modifications would need to be done to an auger motor to use this fuel to make more horsepower that the gasoline baseline motor?

OK, here’s a status update for the afternoon crowd. (lots of good stuff has been posted this morning, so keep it coming!)

On question #1 it has been discussed that E-85 is 85% ethanol and 15% gasoline (thereabouts, depending on the source), and it has a RON octane rating of approximately 105 as opposed to gasoline at about 90. Exactly what that high octane allows us to do has not been fully explored beyond allowing additional timing advance. On the down side it was mentioned that the higher flashpoint of E-85 (as opposed to gasoline) would make it difficult to start a motor on it alone in cold weather. Let’s assume we can get past that by starting the motor on gasoline then switching to the ethanol blend. It was also mentioned that jetting would need to be increased by at least 20%, but I did not see anyone go into why this is the case. This is the second drawback and still needs to be identified.

For modifications, there were several comments about spark, but we should be able do this change with the stock ignition and some adjustment. The addition of turbos, superchargers and laptop tuners were mentioned, but that is not practical on a small two stroke motor, so let’s leave that out for now. Increasing the jetting was mentioned but not really quantified as to how it needs to be done (beyond the number of 20%). We can assume for argument that the materials in the motor are compatible with ethanol, that we can change anything with respect to the stock fuel system, and that the stock ignition timing is adjustable.

So, for the afternoon here are the remaining questions:

1. What changes does the 105 octane allow us to do?

2. What about E-85 requires us to need to increase the jet sizing?

3. What is the primary disadvantage to using E-85 as a fuel?

4. Once these questions are answered, what would be an ideal application for using the E-85 fuel?

Who will take a shot this afternoon!

[Luke_M]

I didn't see any one say anything about one of the worst problems. Ethanol loves water it will absorb moisture from the air. If left to sit ethanol will drop to the bottom of the tank taking all the water with it. When that gets into your carb it causes a lot of corrosion.

[hydro]

Luke, I hoped you would jump in. Yes ethanol has an affinity for water but if we keep condensation to a minimum, the ethanol will actually absorb a small percentage of water and carry it through the combustion process. That is how products like "Heet" work. When the water percentage gets too great it will separate out and cause the problem you describe.

[Scott K]

With higher octane, we can increase compression.

E85 gets about 20% less fuel economy of regular gasoline, so you would need to increase the jet size ti increase the extra amount of fuel needed.

To me the primary disadvantage of using E85 is that it is a solvent, and washes the 2 stroke oil off of the cylinder walls. Along with it absorbing water

I can tell you the best application for using alcohol, it is best served with a soft drink, and ice.

[Black_Bay]

With higher octane, we can increase compression.

E85 gets about 20% less fuel economy of regular gasoline, so you would need to increase the jet size ti increase the extra amount of fuel needed.

To me the primary disadvantage of using E85 is that it is a solvent, and washes the 2 stroke oil off of the cylinder walls. Along with it absorbing water

I can tell you the best application for using alcohol, it is best served with a soft drink, and ice.

Beat me to it. Good answers. E85 might work in a 4 stroke but good luck mixing 2 stroke oil in it.

My buddy and his kids run 5 hp Briggs based Go Karts on 100% ethanol and get 4 times the power out of them. As you say the compression is higher, the jets are larger and he has to change oil after each race day because the alcohol dilutes the oil so badly.

[hydro]

With higher octane, we can increase compression.

Scott you got the #1 afternoon questions remaining point!

Now we need to tie in the reason that jetting needs to be increased. Who can post that one?

[hydro]

Beat me to it. Good answers. E85 might work in a 4 stroke but good luck mixing 2 stroke oil in it.

My buddy and his kids run 5 hp Briggs based Go Karts on 100% ethanol and get 4 times the power out of them. As you say the compression is higher, the jets are larger and he has to change oil after each race day because the alcohol dilutes the oil so badly.

Good point Black Bay, but let's assume we can properly lubricate the engine. When I raced boats, the castor bean based oils held the mix and lubricated well when used with methanol, so let's say we are using bean oil to lube the motors.

[Surface Tension]

Word Clue:

oxygenated gas

[McGurk]

Because there is oxygen in the E85 that wouldn't be in Non-oxy. You need to richen the air/fuel mix to avoid a lean condition and overheating of the cylinder.

Not to nit-pick, but I feel like this dump was answered already when I said a tune-able carb (as in, swapable and adjustable jetting) and tighter rings (higher compression). If you have the answers just let us in on your little game. Lay out what you want to do, as you have already talked up your past in methanol.

I for, spent less than $20 on my 6-yr-old 2hp SM Tecumseh powerhead (with yellow decomp button)and did 5 things to make it a screamer compared to when I first got it. And it's done. Now. Care to venture what 5 things I did? Pretty simple...

[gonehunting]

Wow, I thought the question of how to catch walleyes was hard enough. Good discussion.

[hydro]

McGurk, Sorry if you think this is just a little game, but I am just trying to keep an entertaining discussion rolling. I think enough people have participated to call it a discussion, and nothing I have to say here is really a secret. I will admit that you are on the right track with the “tunable” carb idea but I doubt you could take a Strikemaster carb, tweak the jet needles, and have it work.

Surface Tension, NonOxy gas has nothing to do with it. Sorry.

I will throw out a clue: it has to do with how much energy potential is in the fuel.

[magicstix]

It takes more E85 to make the same btu's as gas or maybe it's cal/btu's.

In alky cars I think it like twice as much fuel as compared to gas. The intake becomes very cold/frosty from the alky changing from liquid to particles.

Higher octane burns slower.

Your timing probably wouldn't change. Compression may need to increase to increase combustion chamber temp. to help light the cold fuel.

Don't alky motors run colder overall.

Just some thoughts been a long time since I've been around a alky car and have forgoteen. I'll be waitng for the final answer.

[Crappyfisherman]

My Nils is very hard starting with Non-Oxy. Went back to 89 oct. and it runs fine.

[hydro]

It takes more E85 to make the same btu's as gas or maybe it's cal/btu's.

In alky cars I think it like twice as much fuel as compared to gas. The intake becomes very cold/frosty from the alky changing from liquid to particles.

[Fishin4fun_MN]

One of the biggest problems with e-85 in small engines, and engines not designed to be used with it is that the ethanol dries out the seals and can even damage and render useless the small plastic carbs. Alcohol actually burns hotter than unleaded. It also burns cleaner. +1 on the washing of the oil off the cylinder walls.

[PurpleFloyd]

It is also more corrosive and is harder on rubber fuel lines if you have them and if I remember right some metals don't like it as much.

[Bass Whacker]

Let me start out by saying this is a great read. I started modifying a model 30 jiffy last year during my spare time at school. I got this auger for free so I figured I wouldnt be out much if I wrecked it. But after a couple hundred dollars in parts and alot of labor I have a pretty mean auger but I always thought of doing this after seeing the power made on e85 in cars.

I have very few awnsers but i do know you will need to flow more fuel 20-30 percent is what I've been told, so larger jets will be needed. a bored over carb throat could possibly flow the extra air needed to get a proper combustion. Porting in the cylinder to properly flow the amount of air/fuel mixture to the cylinder would also be needed.

If we get a answer to this I may just have an auger that is going under the knife again once the season is over and I dont need the auger again for 9 months.

[hydro]

I have very few awnsers but i do know you will need to flow more fuel 20-30 percent is what I've been told, so larger jets will be needed. a bored over carb throat could possibly flow the extra air needed to get a proper combustion. Porting in the cylinder to properly flow the amount of air/fuel mixture to the cylinder would also be needed.

The jetting is the last thing to be resolved here and it is the heart of the process. To burn E-85 you do not need to increase the volumetric efficiency of the motor and to keep the discussion baselined, I will leave the carb bore and porting untouched so that airflow remains a constant.

Any more ideas????

[magicstix]

Because the more fuel/air you can cram into the cyl. = more btu's which = more horsepower. Given the ratio is still 14.7:1. Correct?

If I could use my phone a friend option I could get the rest of the answer but I don't know where hes at right now. My wife hates when he comes back to town because its all gearhead talk.

[hydro]

Because the more fuel/air you can cram into the cyl. = more btu's which = more horsepower. Given the ratio is still 14.7:1. Correct?

magicstix, once again you are right! That ratio he is referring to is the "Stoichiometric Ratio" which is the ratio of how much air is required to completely burn one unit of fuel, and it is an expression of weight. For gasoline it is 14.7:1 or 14.7 pounds of air to burn one pound of gasoline. For E-85, the number changes to 9.76:1. Now these numbers are based on complete combustion, and in the real world that would result in "lean burn" and likely piston damage. In fact numbers where there is more fuel burned per unit of air resulting in a richer mixture make the more power, and are closer to 12.5: 1 for gasoline and 6.975:1 for E-85.

Now, here is where the carb jetting comes into play. The weight difference needed to get the same efficiency in combustion says that we need about 44% more E-85 by weight for the same volume of air going through the motor (this is why air volume was held as a constant). To convert weight to volume so that we can size the jetting, E-85 weighs about 6.8 lbs/gallon, and gasoline weighs about 6 lbs/gallon or .9 times the weight a gallon of E-85.

Since we need 44% more E-85 by weight, we then need to multiply that by the difference in weight for the same volume (.44 X.9) and we get a number of .396 or 40% and that is the amount the area of the jets and the associated fuel passages need to be enlarged to be able to tune in into the correct Stoichiometric Ratio for combustion.

Last question of the night is will this motor configuration make more power than the same configuration running on gasoline?

[Surface Tension]

I didn't say nonoxy gas.

I said oxygenated gas and that is what E15 and E85 are.

Your going to need rejet or if you have a carb with High and Low Speed mixture screws.

Why because at E85 you engine will run too lean.

Other then that all you'll need a oil that won't be washed out by E85.

I went over E15 concerns back in back in 1997.