Any Buddy Get That Great Gas In San Marcos or Austin?

[gsharapa]

First outting for Cobra and really enjoyed the back road cruise to the airport (for pics) and then up to Austin (The OASIS) for lunch with Sammy, John, David and Jay. Car ran exceptional even in the heat until we stopped for gas in Austin on our way back. Had to be Ethanol blended or something as shortly after getting gas the car started to slightly vapor lock and act very erractic during acceleration. After we returned from the cruise and the car was sitting for a short period and the fuel started to boil in the carb. Understand some others experienced the same conditions.....Keith talked to Quickfuel and they told him Ethanol blended fuel will do this in hot conditions.........so off I went today and bought some 107 octaine fuel to kill the Ethanol.......should be fun to drive this weekend!

[jdean]

Gary I got some of that gas a couple of years ago. It percolated and actually caught fire in downtown Austin. Even after we put the fire out it kept boiling out of the idle slots and carb boosters and into the manifold for what seemed like a minute or so. This gushing fuel is a running faucet of gas and can power a very large fire in 2 seconds. Fire was blowing 4 ft. high out of my hood scoop. In my case it was at night, so not even the hottest part of the day. Now I avoid Ethanol completely.

Since hardly any two blends are the same, Gasoline boils over range of temperatures, between 39 and 200o C (102oF and 392o F) typically, the temperature range varies depending upon the brand, octane, and seasonal formulation and how much fuel pressure is feeding the bowls. More pressure equals higher boiling point. Carbs dont have near the pressure as EFI. Ethanol boils at only about 175F at sea level atmospheric pressure. There can be over 200 chemicals in gasoline and many of them, including Ethanol, can dramatically lower the boiling point.

Ethanol gasoline in a carbureted engine, while it easily gets hot, can cause more than one sympton resulting in the engine not running correctly, ranging from cavitation in the fuel pump causing a lean condition, to percolating in the carb causing anything from running rich to mis-firing due to flooding. If it is near boiling while running you may not notice because it is running fine. But when you kill the ignition it will almost always immediatley start percolating and spill into the engine due to loss of fuel pressure and heat soak. Then it becomes flooded and hard to start, AND therefore prone to starting a fire. A fire can start silently in the carb, so it is under the breather and can burn for a while before you even know you have a fire going in there.

If you can easily drain it, you might think about removing it and put it into your daily. It is a real danger in the typical Cobra.

[charles roybal]

The West Texas cobras got gas here... our cars start farting. Mine did not come down until we got gas in Del Rio on our way back home.

[digginfool]

I have boiling issues with my car as well. Unfortunately, no stations in my city carry non-ethanol fuel. There is a VP Racing Fuels distributor about 15 miles away but a real pain to get to. I am thinking about buying a drum of VP but not sure I want a half-empty drum of gas sitting around, if you know what I mean. I've gotten in the habit of turning off my fuel pump about a mile before my destination to drain the level down in the float bowls. Since doing that I haven't had any problems with fuel boiling out of the carbs (I have Webers) and onto the intake manifold.

[Ron61]

I have bought a barrel of 110 leaded racing gas almost every year for the past 10 years. I don't use as much now as I used to as some years I had to buy 2 barrels. but it is worth it as the car seems to gain 100 horsepower with it. I am down to 8 gallons left and am almost afraid to call to have another barrel delivered as I don't know what the price is now.

As for my lawn and garden equipment I buy the 93 octane with no methanol or alcohol in it and what a difference that makes in how it runs. I think everyone but me around here has had to take their equipment in to a small engine repair shop and my neighbor has Sears coming out Friday to work on his tractors as it is missing really bad. Probably some of the rubber hose rotted by the methanol is plugging the carb.

Ron

[Tugboat]

Anyone know of a phone app. that will tell us where the nearest station is WITHOUT ethanol? Ok some of you internet junkies, here is your chance to be a hero.

Larry

[elmariachi]

Originally Posted by Ron61

I have bought a barrel of 110 leaded racing gas almost every year for the past 10 years. I don't use as much now as I used to as some years I had to buy 2 barrels. but it is worth it as the car seems to gain 100 horsepower with it.Ron

You have a V-8 engine that can gain 100 horsepower by going from 93 to 110 octane?

[cgsincc]

Originally Posted by Tugboat

Anyone know of a phone app. that will tell us where the nearest station is WITHOUT ethanol? Ok some of you internet junkies, here is your chance to be a hero.

Larry

I don't know of an app but here is a decent website. http://pure-gas.org/ and a map of all the stations http://pure-gas.org/extensions/map.html

Court

[randlej]

Ethanol Free gas stations. http://pure-gas.org/ Nothing in Houston or Austin.

I live in Austin and have been chasing gas problems the past month. I feel the ethanol situation is only going to get worse. Seriously considering moving over to fuel injection.....

http://www.retrotekspeed.com/product...ii-system.html

http://www.fuelairspark.com/ezefi/default.asp

[mpanten]

I always buy my gas around here at shell beacuse they dont have any ethanol in it. A lot of others have 10% but I have never really had a problem with those either.

[Bwana Snake]

Never used it before but do you think Octane Booster night help or resolve the problem? I think it is readily available and probably a lot cheaper than race gas.

[scaffold]

"buyrealgascom" and "gasbuddy.com".

[elmariachi]

Originally Posted by randlej

I live in Austin and have been chasing gas problems the past month. I feel the ethanol situation is only going to get worse. Seriously considering moving over to fuel injection.

Randy, I am now convinced all your troubles this past weekend (and maybe otherwise) are related to this ethanol. Can you get your hands on some av-gas to try? Or at least find a different place to buy your gas.

Jim

[randlej]

Jim,
Living in Lakeway I just have to drive right over to the airpark 1 mile away and put some in. I'm thinking a 25% mixture.

That said, I don't want to have to do that all the time. Am trying a few things to better isolate my fuel lines and fuel pump from the heat. I even found a phenolic spacer for the mechanical fuel pump. $8. I had never seen one of those before. Worth a shot.

Have also fabbed up an aluminum heat shield for the pump as the problem really seems to ramp up when the fan comes on and blows hot air right on the pump.

Thanks for your help this weekend by the way.

[G_Edmonds]

You big block guys may have problems with boiling but that's not all the problem. The viton needle and seats are not alcohol compatible. They end up sticking open when subjected to alcohol. Obviously causing the bowls to overfill. Thus the flooding symptoms. If that's the only gas available you may have to change to stainless steel needle and seats.
-Greg

[WardL]

So none of you had boiling gasoline problems before there was ethanol? The volatility of the fuel is not that much different with ethanol as refiners adjust the base fuel before adding ethanol. Many areas are transitioning from winter fuel to summer fuel right now. If you happen to buy winter fuel and get into a warmer day or drive a vehicle that has a really hot engine, you are going to be exposed to gasoline boiling over in your carb or vapor lock. These problems will be less of an issue in the summer as the EPA requires all retail sites to be converted to summer gasoline by June 1. I don't mean to defend ethanol, but not sure it is a big part of the boiling gasoline.

[randlej]

That is a very valid point. My car in Austin started acting up last month with the weather heating up early. A quick google search found the following interesting read (btw, is there an additive to combat winter gas??).......
__________________________________________________ _________
A Primer on Gasoline Blending
Gasoline is composed of many different hydrocarbons. Crude oil enters a refinery, and is processed through various units before being blended into gasoline. A refinery may have a fluid catalytic cracker (FCC), an alkylate unit, and a reformer, each of which produces gasoline blending components. Alkylate gasoline, for example, is valuable because it has a very high octane, and can be used to produce high-octane (and higher value) blends. Light straight run gasoline is the least processed stream. It is cheap to produce, but it has a low octane. The person specifying the gasoline blends has to mix all of the components together to meet the product specifications.

There are two very important (although not the only) specifications that need to be met for each gasoline blend. The gasoline needs to have the proper octane, and it needs to have the proper Reid vapor pressure, or RVP. While the octane of a particular grade is constant throughout the year, the RVP spec changes as cooler weather sets in.

The RVP is the vapor pressure of the gasoline blend when the temperature is 100 degrees F. Normal atmospheric pressure varies, but is usually around 14.7 lbs per square inch (psi). Atmospheric pressure is caused by the weight of the air over our heads. If a liquid has a vapor pressure of greater than local atmospheric pressure, that liquid boils. For example, when you heat a pot of water, the vapor pressure increases until it reaches atmospheric pressure. At that point, the water begins to boil.

In the summer, when temperatures can exceed 100 degrees F in many locations, it is important that the RVP of gasoline is well below 14.7. Otherwise, it can pressure up your gas tanks and gas cans, and it can boil in open containers. Gas that is boiled off ends up in the atmosphere, and contributes to air pollution. Therefore, the EPA has declared that summer gasoline blends may not exceed 7.8 psi in some locations, and 9.0 psi in others.

A typical summer gasoline blend might consist of 40% FCC gas, 25% straight run gas, 15% alkylate, 18% reformate, and 2% butane. The RVP of the gasoline blend depends on how much of each component is in the blend, and what the RVP is of each component. Butane is a relatively inexpensive ingredient in gasoline, but it has the highest vapor pressure at around 52 psi.

In a gasoline blend, each component contributes a fraction to the overall RVP. In the case of butane, if there is 10% butane in the blend, it will contribute around 5.2 psi (10% of 52 psi) to the overall blend. (In reality, it is slightly more complicated than this, because some components interact with each other which can affect the expected RVP). This means that in the summer, the butane fraction must be very low in the gasoline, or the overall RVP of the blend will be too high. That is the primary difference between winter and summer gasoline blends.

[tomh440]

Maybe we are in the middle of a switch over in gas? Possibly why 2 station were out of gas in San Marcos?
Its cool today, I think i'll take a ride in the car to see if it acts better. Hey, any excuse to go for a ride!

[elmariachi]

Thanks for this Randy, its very informative. No doubt the entire area is suffering from something similar based on the widespread issues you were all seeing.

[gsharapa]

I ended up putting 5 gallons of 107 leaded in mine last weekend and it cured my issues as it was upper 80s when I came back from lunch. Put another 3 gallons in last night so should be ready to go this weekend. I plan to buy another 10 gallons of 107 and mix 2 or 3 gallons with every fill up of 93 octaine from the pumps. Funny....the 107 was only $ 6.23 a gallon and the why Obama is going 93 will be there shortly!