Gas (Beating a dead horse)

[ClownColor]

So once again I've started questioning my own practices. I've been pretty strict on running non-oxy fuel in my small engines, boat motor, sled, and atv as they sit for extended periods of time. Why? well because I've read that the non-oxy gas doesn't dry out gaskets and seals while sitting for long periods of time. This is true.

But can a ETOH guy explain why gas "sitting" in a motor vs gas "running through" a motor is any different? If my gas tank always has regular gas in it, regardless if I keep adding more or if it's just the same regular gas that's been in there over a month, why would one ruin and dry out my seals over the other?

Aren't ETOH and water soluble causing it not to separate? If so, would the argument for people that say it's because the regular gas is breaking down, separating the ETOH, which is then break down the rubber seals a false statement?

I guess from some articles I've read, it states older vehicles should run non-oxy cause it will dry out gaskets...it doesn't say older vehicles should use it just for storage. Meaning, regardless if it sits or is running, the regular gas can cause harm...but with newer rubbers, regular gas is fine...so I'd think regular gas would have the same affect on your seals if your constantly filling and re-fill or if it's just sitting there.

Well???

[Ufatz]

Sheeeet fahr, ya got me?

[Surface Tension]

Modern seals, diaphragms, fuel lines are supposed to be alcohol resistant.

Oxy fuel breaks down sooner then non oxy fuel but a fuel stabilizer should be used in both for extended storage.

Oxy fuel will absorb moister from the air and one reason I don't like storing it in a fuel tank that is vented. All onboard fuel tanks are vented. Fuel tanks in boats are perfect for this absorption as they have a huge surface area exposed to the atmosphere because of they're long flat shape.

Fuel sitting in a carb for extended periods of time and fuel being run through a carb is different. That stale fuel will varnish are carb, tarnish brass parts, and oxidize aluminum. That would happen with both fuels. Now add water with the gas and you have rust.

How does water get in the gas tank.

You can get it from the pump.

Condensation. Imagine a vented fuel tank half full.

At night it gets down to 40 degrees and during the day it rises to 80.

This happens with both fuels but the vented tank with oxy fuel is also taking the moister from the air as well. Water will mix with oxy gas. Water will settle in a tank with non oxy gas.

Which is better? You might say the fuel that mixes with water but remember that fuel will take it from the atmosphere too.

Back to alcohol resistant fuel lines, diaphragms, and gaskets.

Very good chance that the OME parts are but when you buy aftermarket parts, its a carp shoot.

Where are these aftermarket parts made?

Some aftermarket fuel line, bulb w/fittings have shown to not last with inner core deteriorating and swelling.

[delcecchi]

As I understand it, some materials that are fine with gasoline degrade when exposed to ethanol. These materials were widely used in motors and fuel systems before ethanol was added to gasoline.

Also ethanol dissolves stuff that gasoline doesn't so if there is crud in the system it might get knocked loose by the ethanol.

[ClownColor]

Good info and thanks Surface Tension.

I'm still on the fence about if it's truley needed. I run my boat a minimum of two weekends a month during the season and it's stored during the winter months almost full...I imagine you don't get to much condensate during winter months. I always toss in sea-foam. But...there is ETOH in sea-foam as well, just not alot.

I've also been curious if a boat would run better on the blend it's set-up for. Mines set for 87 octane and most non-oxy is 91-92.

Just another one for you...

Whats better: 92 non-oxy gas OR 87 regular with a stabilizer added?

[ClownColor]

As I understand it, some materials that are fine with gasoline degrade when exposed to ethanol. These materials were widely used in motors and fuel systems before ethanol was added to gasoline.

Also ethanol dissolves stuff that gasoline doesn't so if there is crud in the system it might get knocked loose by the ethanol.

That was kind of my point...but why does sitting gas ruin more then working gas (both of course being regular). Surface Tension did a good job explaining it.

Thanks

[Surface Tension]

Finding a non oxy 87 octane around my parts is impossible to find and that would be the best. How often you go through a tank of gas matters if you need to add a stabilizer with either blends.

Sine we're on the subject about a stabilizer. Sta-bil Marine is intended for exactly what

the concerns I mentioned. Here is a cut and paste.

Q: What is the difference between Marine Formula STA-BIIL®, STA-BIL® Fuel Stabilizer, and the new STA-BIL® Ethanol Treatment products?

A: Marine Formula STA-BIL® Ethanol Treatment was designed for use at every fill up for marine engines (boats, jetskis) to protect against the damaging effects experienced when using Ethanol blended fuels -- including corrosion caused by water attraction, and fuel system plugging caused by deposit loosening.

STA-BIL® Fuel Stabilizer is designed for use during STORAGE of any gasoline equipment or vehicle stored for 30 days or more, or used infrequently. It will keep gas fresh for 12 months, and help prevent corrosion, and gum and varnish formation.

New STA-BIL® Ethanol Treatment is designed for use at every fill up for all gasoline automotive and small engines for protection against these same problems.

All STA-BIL® brand products are effective in all gasolines, including Ethanol blends, including E-85

[boatfixer]

+1 on Franks comments.

The other thing to mention is phase separation. Lower grade gasoline with segregate over time as well as attract moisture. The marine stabil frank mention is supposed to address this issue. I've been using now for a few years in all my small engine cans as when I winterize boats in the fall.

91 octane will not enhance performance (typically). Its a slower burning fuel and pretty much all modern engines do not have the compression to take advantage of the increased octane.

[fishingstar]

What is the self life of non-oxy gas? I talked to one of the more popular local guys that have it and he said they only fill the tank (looks like 500 gal tank) 3 to 4 times a summer. I stooped using it because my gas does not sit around.

[PurpleFloyd]

I am not going to comment on the effect ethanol has on gaskets etc as I don't have much experience with that subject.

However, the whole association of ethanol and water has been stretched and contorted over the years into something it isn't. Most of the talk revolves around water in the gas and it is important to understand this relationship to be able to separate the fly specs from the pepper. First off, if you have vented gas tanks or expose them to conditions that can cause condensation you are getting water in your gas whether it has ethanol or not. This has always been the case and if you look back to the days before ethanol was added to gas, you often needed to add HEET or similar products to the gas. Why was this done? Simple- Heat contained IPA or Isopropyl Alcohol which is one molecule different in the chain than Ethanol. Isopropyl alcohol bonded with the water and kept it from freezing in the fuel lines and preventing the vehicle from starting. Since ethanol was added there is not the need for HEET type products because it does the same thing.

Now, at some point you can get to where the ethanol has bonded as much water as it can. At that point any additional water will just settle at the bottom of the tank. When this happens the water will be much as it would be if no ethanol or IPA was present in the gas. This gets referred to as Phase separation.

The solution to not getting water in the gas is to prevent condensation so keep the tank full which will keep the amount of water containing air out of the tank and reduce the water that gets introduced.

There are additives on the market that play into many of the myths that are spread about the relationship of water to ethanol. If you look closely into their ingredients they also contain some type of alcohol to lock up the water which essentially just makes a blend like e-10 into e-12 or whatever depending on how much you add and what that does is increase the amount of water that can be held in the gas before it hits saturation but do nothing to fix anything except that. They also contain ingredients like turpentine and mineral spirits or similar additives that are widely available at a fraction of the price at the paint store.

[delcecchi]

I have lived in Minnesota for many years, never used heet in my cars and was just fine. Condensation as a problem is vastly over rated. See my post of a good while ago about the actual moisture content of air or do the calculation of how much water enters a gas tank due to temperature cycling.

The people I know who have had water in the gas issues either got bad gas from the supplier or left the gas in the tank for a very long time. Like years.

Most of the heet and seafoam type things are in the "mouse milk" or "magic chemicals" category, in my opinion.

[TruthWalleyes]

I am not going to comment on the effect ethanol has on gaskets etc as I don't have much experience with that subject.

However, the whole association of ethanol and water has been stretched and contorted over the years into something it isn't. Most of the talk revolves around water in the gas and it is important to understand this relationship to be able to separate the fly specs from the pepper. First off, if you have vented gas tanks or expose them to conditions that can cause condensation you are getting water in your gas whether it has ethanol or not. This has always been the case and if you look back to the days before ethanol was added to gas, you often needed to add HEET or similar products to the gas. Why was this done? Simple- Heat contained IPA or Isopropyl Alcohol which is one molecule different in the chain than Ethanol. Isopropyl alcohol bonded with the water and kept it from freezing in the fuel lines and preventing the vehicle from starting. Since ethanol was added there is not the need for HEET type products because it does the same thing.

Now, at some point you can get to where the ethanol has bonded as much water as it can. At that point any additional water will just settle at the bottom of the tank. When this happens the water will be much as it would be if no ethanol or IPA was present in the gas. This gets referred to as Phase separation.

The solution to not getting water in the gas is to prevent condensation so keep the tank full which will keep the amount of water containing air out of the tank and reduce the water that gets introduced.

There are additives on the market that play into many of the myths that are spread about the relationship of water to ethanol. If you look closely into their ingredients they also contain some type of alcohol to lock up the water which essentially just makes a blend like e-10 into e-12 or whatever depending on how much you add and what that does is increase the amount of water that can be held in the gas before it hits saturation but do nothing to fix anything except that. They also contain ingredients like turpentine and mineral spirits or similar additives that are widely available at a fraction of the price at the paint store.

Bingo.

In my experiements in college, you can measure the concentration of ethonal by adding water until the point that water is no longer absorbed into the gas. A little math, and you've found your ethonal concentration.

Extensive tests were done within automotive engineering department with all the various additives and most of which do not do what is advertised on the label. All the gas station little containers that improve this or that was just a joke.