by Dave Searle

E10 FUEL, CONTAINING 10% ethanol,is now the only fuel sold across themajority of the country. And E15 is

coming. Pushed by the ethanol lobby, ithas received EPA approval for 2001 andnewer automobiles despite the fact that thecar manufacturers don’t want it and it isnot approved for use by any motorcycleOEM either. Because the fuel hose onmost gas pumps contains about three-quarters of a gallon of whatever was soldpreviously, to accommodate motorcy-clists, E15 will be restricted to sales offour gallons or more so that motorcycleswon’t be filled inadvertently with muchmore ethanol than their bikes are allowed.Comforting, no? Does your motorcycleeven have a tank bigger than four gallons?

As my September 2012 Open Roadcolumn revealed, the problems with gaso-line/ethanol blends include phase separation,which happens when the ethanol (which ishygroscopic, meaning it has an affinity forwater) has absorbed enough atmosphericmoisture to fall out of suspension with thegasoline. We’re told the precise amount ofwater required to affect this separationdepends on temperature. At 60° F, it’s saidto take just .45% water to create separation,slightly more at higher temperatures andeven less at lower temperatures. Exposure toa breeze will also accelerate water conden-sation, as the ethanol will chill the fuel con-tainer, creating beads of water on its walls.

Of course, most new motorcycles aswell as cars have essentially sealed fuelsystems that prevent much contactbetween the fuel and the atmosphere, sophase separation is less of a problem.

However, many of us own older motor-cycles with fuel vents that aren’t so partic-

ular, and many of these are powered bytwo-stroke engines. Two-strokes haveadditional problems due to the fact thatethanol breaks down the effective lubri-cation of fuel/oil mixtures, leading toseizures. I’d never seized my go-kartengine until I first used E10 in premix.

Corrosion is the other problem. E10 isparticularly corrosive to plastics, rubber,aluminum and fiberglass compared tostraight gasoline, and the mixture of waterand ethanol that settles to the bottom ofthe gastank when E10 phase separates ispossibly even more corrosive.

While a phase-separated mixture ofalcohol and water is supposedly actuallycombustible in an engine, it would createa much leaner mixture than E10 or gaso-line, with the potential for engine damagefrom high temperatures.

And it’s not just the fiberglass tanks onvintage bikes that experience ethanolissues. The swollen gastanks on late modelDucati Sport Classics are also caused byethanol. Thankfully, the reason that mostaftermarket plastic gas tanks don’t reactthe same way is that they are made from adifferent polymer formulation. The Ducatitanks couldn’t share this type because theyneeded to be paintable.

When E10 is allowed to sit for a longtime in a fuel system, the volatile portionof the fuel will eventually evaporate, leav-ing a milky residue behind. And this goowill eventually harden into an amber solidthat cracks into tiny pieces—creating amass of insoluble debris that must bephysically removed before the engine canbe brought back to life.

As the problems that E10 creates withsmall engines and also with marine engines(which naturally have much greater atmos-pheric exposure to moisture than land vehi-

cles) are well documented, let’s say you’dlike to run your vintage dirt bike, personalwatercraft, snowmobile, go-kart, lawnequipment or other machine on pure gas,but it’s either not available in your area(see pure-gas.org) or you would have tobuy expensive race gas to have ethanol-free fuel. In fact, it’s possible to removethe ethanol from E10 fairly easily, leavingyou with pure gasoline and a small quan-tity of left-over water/ethanol.

Removing EthanolSince phase separation happens natu-

rally to E10 when exposed to water, allyou have to do is deliberately introducea small quantity of water into a quantityof E10, shake or stir and wait for it toseparate; the lighter gasoline will rise tothe top, leaving the heavier water/ethanolon the bottom.

We’ve illustrated the procedure with alaboratory device called a separatory fun-nel, a bottle with a screw-on cap and atapered bottom that ends in a valve, whichallows the separated water/ethanol to bedrawn off precisely.

We first tested the claim that as little as.45% water at 60°F will create phase sep-aration. As our ambient temperature wasslightly higher, we used .5%. To start, weadded 500cc (one-half liter) to our separa-tory funnel, and added .5% water, which is2.5cc. We used the same 25cc graduatedburette we used for combustion chambermeasurement for accurate water dispens-ing. The funnel was then capped andshaken to achieve mixing. Phase separa-tion happened within a matter of minutes.However, the amount of water/ethanolseparated was much less than the 10%anticipated, just 8.6cc instead of the 50ccthat E10 would be expected to contain.

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This result suggests partial phase separa-tion, which might also be expected to hap-pen with even smaller amounts of water.So we tried a second test with 5cc of waterin 500cc of E10. This time, the amountseparated was 48cc, nearly the 50cc we’dexpected. But, as you can’t be absolutelysure the gas pumps have added just the10% ethanol allowed by law in E10 fuel,we’d suggest an even larger quantity ofwater (say 2%) if all you want to do isremove all the ethanol. (Per gallon, 2%would be 75.7cc or 2.56 oz. of water, and5 tablespoons, equal to 2.5 oz., is close.)

Determining EthanolConcentrations

If you have a few relatively inexpen-sive lab tools, it’s also possible to deter-mine the actual quantity of ethanol in agiven sample of E10. Starting with our500cc separatory funnel, a 500cc gradu-ated cylinder and a 25cc burette (seephoto), we’d suggest you add exactly 10ccof water to 500cc of E10, stir vigorouslyand wait for the ethanol to fully separate(an hour will probably be plenty of time).

To measure the ethanol, first fill yourgraduated burette to the bottom 25cc markwith water, and with it resting upright(inside the graduated cylinder is handy),

you can carefully dispense the cloudyethanol/water portion into the burette,being careful to stop when it reaches thezero mark. Because you’d expect to collect50cc of ethanol and 10cc of water, you willprobably have to fill the burette more thanonce. Each time, note the amount of milkywater/ethanol in the sample, draw off thelower portion of water in the burette andthen save the separated ethanol/water in aclosed container. Refill the burette withwater to the 25cc mark before repeating

the technique. Ideally, you will collect60cc of water/ethanol from a 500cc sampleof E10 if it truly contains 10% ethanol.With good tools, you can separate withoutcreating toxic waste. The ethanol is onlygrain alcohol, now suspended in water, andthe gasoline is reused.

Final ThoughtsTo achieve high octane, your separated

pure gas should be dosed with octanebooster to replace the ethanol’s contribu-tion. Although our quantities were admit-tedly small, to speed the process, we’drecommend 5-gal. glass or PET plasticjugs (see eBay or beer brewing supplierslike midwestsupplies.com) fitted withstopcocks and vent tubes. At this size, youcan quickly and easily make all the puregasoline you want and forget aboutethanol’s problems.

RESOURCESNova Tech Intl.—Laboratory Supplies.Separatory Funnels 500cc: glass $31.87;plastic $20.62. Graduated Cylinders 500cc:Glass $26.10; plastic $6.48. Burettes 25cc:Glass $27.69. Phone: 866-433-6682; novatech-usa.com

Our chemistry set included a 500cc grad-uated cylinder for measuring fuel; a 25ccburette for accurately adding water, andmeasuring separated water, gas andwater/ethanol; and a separatory funnel todrain the phase-separated water-ethanol.

Pure ethanol is ~113 octane, so remov-ing it from E10 will reduce octane, turn-ing premium to regular. To re-achievehigh octane, a booster must be added.

Separation byspecific gravity:Water at thebottom, milkywater/ethanol inthe middle andstraight gas atthe top.

Although our cheap plastic separa-tory funnel isn’t crystal clear, youcan clearly see the water/ethanolat the bottom.

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