E-10 Effects

[maineSS]

Just read about the effects E-10 gasoline (10% Ethanol blend) is having on the Marine Industry- rather ugly. Basically older rubber parts, fiberglass fuel tanks, and uncoated steel surfaces are at risk. I'm going to replace the rubber sections of fuel line, look at my fuel pump internals, fit a supplemental filter with replaceable element, and look at gas stabilizer additive. Anyone have any nasty experiences yet?

[greg rider]

That is why drag racers have way different carbs. The ethanol will ruin regular rubber parts. The newer cars on the road have the proper parts to deal with this. I don't know if any of the gas additives cover this.

[maineSS]

The B&B carb doesn't appear to have any problem parts- the accel pump skirt is leather, the float is brass, and the float inlet and stepup jet needles are brass or brass/viton. The diaphram in the fuel pump, any rubber lines, and any deposits in the steel lines and gas tank are another matter. I'm seeing more stuff in the sediment bowl, so I'm going to be watching the weep hole in the fuel pump closely, and checking the oil for gas smell. I'm going to try Sea Foam for awhile, and see what that does. The Tech claims it helps moderate ethanol's effect on elastomers, but I think the long term solution is replacement.

[maineSS]

I replaced the fuel pump on the PW- it was still good, but I didn't know if the valves & diaphram were E-10 proof. Added a fuel pressure regulator to the carb set to 4 PSI. Also drilled out the main jet 1.5 thou oversize with a specially made up drill, and drilled the stepup jet out 1.7 thou over with a 1.33 mm metric number drill from McMaster-Carr. I can run less choke, but still may need more drilling. I hooked up a vacuum guage and confirmed no manifold air leaks. I'm going to try resetting the idle speed to highest vacuum, and play with the timing- if this rain will ever let up- 21 days of rain in June, 5 days so far for July!!!! Mileage is presently about 5 mpg, compared with 10+ on regular gas. One very strange thing- gas from the tank is water-clear in my glass fuel filter just before the carb on engine shutdown. After 5 hrs sitting it turns yellow. The Seafoam tech said that doesn't happen with regular gas/Seafoam. Anyone else see this?

[74w300uteline]

yellowish color

ethanols solvent properties may be dissolving varnish and deposits from the good old days. just a guess

[chriscase]

I haven't found any pump mfg that tells what his diaphragms are made of.

I haven't found any pump mfg that tells what his diaphragms are made of. Has anybody else?

From my reading, just about all of modern the materials EXCEPT LEATHER and natural rubber, are ethanol proof.

So any pump made after WWII ought to be OK.

Pumps have always been problematical. Even the clumkers I bought in the '70s came with several old pumps under the seat. And electrics installed. I suspect that there is currently a lot of "My pump died, it must be the E, not just a bad pump". Likewise, without any statements of what the mfg uses, I suspect more salesmanship than actual difference.

[maineSS]

That's interesting- leather is supposedly unaffected by ethanol as far I've heard. The accel pump seal is leather, so if ethanol does eat leather, us old carb users are in trouble. High concentrations of ethanol will attack aluminum, so carb castings may be at risk.

[Doc Dave]

Maine,
I don't know about alcohol dissolving leather, but I would assume that alcohol, like other solvents, may make leather brittle and harder over time, which would effect its function as an accelerator pump seal. I am sure you recall the thread I posted when I rebuilt my carb with a new carb kit (and new leather acc pump) the leather was too "new" and stiff so the acc pump did not work properly. Anything that makes the leather less supple could be a problem.
When I was younger I used to make leather belts and other items for a hobby, and it is well known in that trade that after dying with a solvent based product, you needed to oil the leather to restore the natural oils the solvent took out in order to restore it and lengthen its life.
So, would old carb trucks using E10 have to periodically have the carb partially apart to soak the leather in (preferably) neatsfoot oil from a leather shop, or mineral oil if that is not available?
I guess the answer is that alcohol might cause a deleterious effect to the leather. What does alcohol do to rubber and aluminum?

[Clint Dixon]

Maine,
I don't know about alcohol dissolving leather, but I would assume that alcohol, like other solvents, may make leather brittle and harder over time, which would effect its function as an accelerator pump seal. I am sure you recall the thread I posted when I rebuilt my carb with a new carb kit (and new leather acc pump) the leather was too "new" and stiff so the acc pump did not work properly. Anything that makes the leather less supple could be a problem.
When I was younger I used to make leather belts and other items for a hobby, and it is well known in that trade that after dying with a solvent based product, you needed to oil the leather to restore the natural oils the solvent took out in order to restore it and lengthen its life.
So, would old carb trucks using E10 have to periodically have the carb partially apart to soak the leather in (preferably) neatsfoot oil from a leather shop, or mineral oil if that is not available?
I guess the answer is that alcohol might cause a deleterious effect to the leather. What does alcohol do to rubber and aluminum?

I have been burning gasoline containing alcohol since it became available here in the Midwest. I have never had an accelerator pump leather harden, or a fuel pump diaphram deteriorate. I am still running one pump that now has about 20 years and 40,000 miles on it.

I am also adding a lead substitute religiously every time I top off the fuel tanks. I wonder if this substance is also providing a side benefit of offering some "softening" to the accelarator pump leather and fuel pump diaphram?

[Desoto61]

I have been burning gasoline containing alcohol since it became available here in the Midwest. I have never had an accelerator pump leather harden, or a fuel pump diaphram deteriorate. I am still running one pump that now has about 20 years and 40,000 miles on it.

I am also adding a lead substitute religiously every time I top off the fuel tanks. I wonder if this substance is also providing a side benefit of offering some "softening" to the accelarator pump leather and fuel pump diaphram?

I've been using the additive for my Desoto too (which also uses leather for the accel pump), though for probably about half that time/mileage, and have had no issues either.

Does the amount of ethanol vary by octane rating? I know ethanol boosts octane, wonder if the higher octanes have higher concentrations?

[Doc Dave]

The deleterious effects of solvents like alcohol on leather is noted with pure solvent. I am not sure if only 10% ethanol will hurt it that much.
What does ethanol at this concentration do to rubber?

[maineSS]

Gasoline has gotten more aggresive at elastomer deterioration since lead phased out. Octane has been provided ethanol or aromatic compounds, and some of the aromatics are harder on seals and hoses than ethanol. Natural rubber, fiberglass resin used before the mid 90's, and synthetic rubber made before the mid 80's are most at risk. As the ethanol concentration increases, the risk to these parts rises. Right now, 10% seems to be about as high as most engine makers are willing to warranty for.

Sea Foam supposedly has a top end lubricant that helps protect elastomers, and Marvel Mystery Oil added to fuel as a top end lubricant might also help.



I've read a lot of accounts of decreased gas mileage in modern engines (10-20%)- experienced by people who track their mileage for business reasons. This is far higher than the theoretical 3-5% loss. I'm beginning to wonder if the oil companies have found their Holy Grail- a slow-burning fuel with a limited octane. Today's engine use a knock sensor to continuously adjust timing for changing octane, so the timing is advanced to get sufficient burn time with a slow burning fuel, and higher octane has always been slower burning. If the octane value was seperate from burn time, you'd need to change exhaust timing to get all the available fuel energy- presently impactical on 99.99% of today's cars.

Ethanol is presently limited to adding a 3% oxygen content to gasoline. It has an octane rating of 117, and provides most of the needed octane boost to raw gasoline. If you were to add about 4 teaspoons of water to a gallon of gas, you could separate most of the ethanol out, and lose 2-3 octane points. However, the PW flatheads use 70 octane fuel, so they'd probably never notice it. Over time, you'd accumulate a quantity of denatured alcohol to dispose of- perhaps you could imitate the gas flares at oilfields with decorative alcohol lamps?

[maineSS]

Here's the latest on my E10 carb mods- I reset the idle jet with to the highest steady reading on my vacuum gauge, which was two complete turns out. The normal adjustment is 1-1.5 turns out. Tach rpm is 500, normal range is 450- 500. I may try taking the main jet out another 1/2 thou to .002" oversize, and back off on the idle jet.

I was talking with an old time Dodge racer, and he said he used a vacuum gauge to time his engine. He also ran rather more advance than normally reccomended- between 6-10 deg! He would turn the distributor counterclockwise while watching his vacuum until the engine began running rough, then he would split the difference between the beginning reading and the advanced one. Generally this would bring the idle up 100-125 rpm. Then he would drive the car and listen for detonation. He preferred this way over using a light due to the difficulty in getting an accurate timing mark reading (I can relate!).

I also found there is ONE place in Maine where you can get non-ethanol fuel- 93 octane. It's about 110 miles NW of me, at Norridgewock airport. A couple of legislators were going to intoroduce a bill last session to require non-E10 gas to be available along with E-10, so Irving Oil agreed to bring some in to a central point. The legislators will be introducing the bill in January, so hopefully people will be sufficiently fed up to support it.

[maineSS]

Well, we found the rich limit on main jet oversize- it's 4 thou larger than the standard size. About 1/16" dia seemed to be good for E10 on the E7S1 carb- but now I'm back on stock main jet size because the ethanol content suddenly decreased to 5%- EVERYWHERE. I got an alcohol test tube from a local small engine dealer, and checked samples from four national companies, and two independents- all were exactly 5% with the exception of one independent which was 6%. The uniformity is amazing- they must not be splash blending anymore! My mileage went up from 4-5 to 6 to 8.8 over my test period. Not having the choke 1/2 out really helps. After I get the power steering gear fixed so it's not turning left, I should gain a bit more.