Using E85 as an octane booster.

I've been thinking of useng E85 to up octane. Until I ran across this article I was just guessing that it might.

I have a 20 hp kohler command that I can't lean out the carb. It has no adjustments.

I think I may start out blending E85 with my gas, E10, to make E15 and go from there.

I know of a farmer who makes his own E30. He claims it's the best bang for the Buck.

I'm not concerned about E15 or even E20 doing any damage.

Please tell me the good, bad and ugly of blending fuels. Sure there will be more ugly than good.

Does anyone have another sight that may be more helpful?

George
blending E85

Why not run some non ethanol blended gas? I've had good luck using it in my small engines. No more pre-ignition,no more dieseling or backfiring on shut down. My results are based on a 3 cylinder Kubota gas in my Steiner lawn mower, my Miller welder with a 20 hp Kohler, a 20 hp Briggs in a Terramite, and my weed eaters and chainsaws. As an added benefit no more sticky gummy carbs,or hard starting especially in the 2 cycle equipment even if gas has been left in over a several month period. I'll happily pay a few cents more per gallon for it.

I don't have a choice, epa formulated E10. Plus I want to lean out an engine that has no carb adjustments.

The article said that by blending e85, I can lean out engine and have a higher octane, so there is less chance of detionation.

If your engine is running rich and you can't lean it out have you ever thought of going one heat range hotter spark plug ?

The more ethanol you add, the more likely separation will occur,especially if the "gas" is not used within 80-100 days.Best case scenario ethanol gas has a shelf life of 100 days.This is why it is recommended that the fuel be used in 80-100 days or drained out and fresh fuel added.The longer it sits,the more moisture it draws, which causes the sludgy residue,hard starting,and poor performance. The ethanol drops to the bottom of the tank and absorbs moisture which effectively lowers the octane rating 2-4+ points....so your 87 octane fuel now becomes 83-85 octane, which in an engine without knock sensors and variably adjustable timing will cause severe engine damage ie. holed pistons,excessive pinging,sticking valves or worse.

If you have kohler Command and it is running rich, you either have a leak in the carburetor, a bad needle valve, a bad float, a crankcase full of fuel, or else your air filter is stopped up. Assuming you didn't drill the jets because they got stopped up.

why don't you fix the problem instead of doing a witches brew home remedy approach?

Everything Kohler says about ethanol is it causes higher combustion chamber temperatures and that shortens engine life. My experience says that you will eventually have problems with water in the fuel.

As you know for gasoline the stoichiometric air/fuel ratio is 14.7 to 1.0 and for ethanol the air/fuel ratio is 9.0 to 1.0. Therefore, adding ethanol to gasoline will cause the mixture to lean out when using a fixed orifice carburetor. That is to say ethanol requires a larger orifice to flow more fuel.

For 10 gallons of E-10 we have; 1 gallon of ethanol and 9 gallons of gasoline. Therefore, the stoichiometric ratio becomes, [(9 x 14.7) + (1 x 9.0)] / 10 = 14.1 or a lean out of approximately 4%. Most engines can tolerate this which is why E-10 can be used in carbureted engines designed for gasoline only.

The octane rating of ethanol is 105 to 110 so as you increase the ethanol percentage the octane rating of the ethanol/gasoilne mixture moves toward that of straight ethanol.

Ethanol cools the intake charge due to it's higher latent heat of vaporization, 396 btu/lb versus 150 btu/lb for gasoline. Therefore, the engine combustion temperature is reduced over that for gasoline alone.

As for the separation issue I would suggest you experiment for yourself (you will anyway) with various ethanol/gasoline percentages by adding water to them. Compare the ethanol/gasoline mixtures to straight gasoline - I think you will be surprised how well the ethanol mixtures tolerate water.

As for ethanol damage to rubber components, if you are concerned, simply install a shut off in the fuel line. Shut off the fuel and run the system dry before shutting down or long term storage.

Oh and give us a full report of your results.

Indiana Ken,

Thanks for your reply. You are right, I plan to
start with E15.

My terramite, which has the kohler, comes with a
gas solenoid. Currently, I'm removing power to the
solenoid and the engine turns off in about 5
secconds, no dieseling with no gas. However I
would like to lean it out a little.

When I purchased it 6 years ago, the spark plug on
the left cylinder was carboned up, wasn't working.
It took me a while to discover that a single carb
could be rich on the left cylinder and lean on the
right cylinder. Cause was a dirty carb, which I
cleaned with 3 blasts of air in the 3 tiny
openings on top of the carb. So when it acts up a
little, I clean the dirt out of the tiny openings
with air. Doing that I can see a spray of gas
coming out in the venture.


Without an exhaust gas analizer, I have no real
way to measure my expermintal results. The exhaust
temp gauge won't work well here. The engine rarely
has to run very fast to operate the hydraulics.
The loads vary depending on what I'm doing.

I purchased new plugs. Guess I'll have to keep an
eye on them. Also I could use the kill wire on
coils to shut it off after running it hard to see
if it diesels. My old plugs don't look bad, but
when I was having a carbon problem I went with the
next step hotter plug, which may be one of the
reasons for the dieseling.

Thanks for the chat.
George

You have not explained why you think you need to use high-octane fuel in your small gas engine. Is it knocking? If so, why don't you try running a tank of regular unleaded premium before you try your E85 experimentation on an engine that wasn't designed to handle anything above E10?

Dieseling, a little carbon build up on top of piston. And because I want too, can't help myself, have to experiment.

(quoted from post at 15:02:41 07/27/14) I don't have a choice, epa formulated E10. Plus I want to lean out an engine that has no carb adjustments.

The article said that by blending e85, I can lean out engine and have a higher octane, so there is less chance of detionation.

Click to expand...

George-You won't have any problems. E85 has a lot of spare octane. I have done both large and small scale blending work for years. At a local refinery I was responsible for making spec blends on 40,000 Barrel batches(42 gallon per barrel).In the lab we did small 1 gallon blends for testing.That is how the refineries make octane specs now, they add ethanol to make 87 octane out of base gasolines. Phase separation can only happen when you have large volumes of water involved. I am sure your tanks aren't loaded with water. Bear in mind that the allowable water spec for E85 is 1%, but that still should not be a problem. Ethanol will mix with gasoline or water. If you mix it with gasoline there will be no problem. Sloppy tanks with a ton of water in them can cause problems, but I am certain you know what your tanks are like.
(fuelsandlubestechnologies.org)