Gas boiling in tank on hot day

[woodybelle]

Today is the first day I rode with my new Bagster tank cover. I rode 40 miles at temps over 113 degrees F. When I got home the bike was making a gurgling sound from the gas tank. I slowly opened the gas cap and heard pressure releasing and then it spewed gas out of the filler neck like a geyser. I quickly closed the gas cap and then listened to the gas boil in the tank for the next 10 minutes or so.The tank under the cover was too hot to touch. It's supposed to be hot again tomorrow so I'll ride without the cover on the tank to see if it makes a difference. Has anyone else had a similar situation? My bike is a 2006 with 3000 miles on it. The temp gauge was at 3 bars which is normal for me.

[huxtablejones]

just out of curiosity - what was the fuel level in the tank?

I'm thinking a pressurized fuel tank should be good for 5-8 horsepower.

:D

[jeffmiller]

Correct me if I am wrong Paul, but in my experience if you have a boiling gas problem, that can weaken the walls of the tank at some point and cause what we would in the fire/police/ems community, a BLEVE (boiling liquid, expanding vapor explosion).

[RibsST1300]

Are you sure the gurgling wasn't the air trying to escape through the vent hose. Make sure it is not pinched-you don't want too much pressure building either way-positive or negative!!

[STumpy]

I have had it where the tank was very hot to the touch, but no gurgling or boiling gas problem. That just doesn't sound right. I think you should have it checked out.

[ST1300 Alicia]

Maybe the tank cover is stopping the normal heat dissipation from the fuel tank. The fuel rail should be a return type system where fuel is constantly returned to the tank. If you insulate the tank, it has no way to dissipate the engine heat it picked up. Remember this engine builds a lot of heat, 125 horsepower and the heat has to go somewhere. That somewhere is to the riders area. Just a fact of riding a fast high horsepower sport-bike. Internal combustion engines are only about 10% thermally efficient, meaning the rest of the heat energy is lost through the cooling system and friction. Much of the heat energy lost through the cooling system is lost through the radiator. Some HEAT goes out through the exhaust, that is free energy we sometimes use to power a turbocharger. If you were to watch an EGT sensor graph you would see a temperature drop across the turbine. I think we just need to let this bike effectively dissipate it's excess heat and dress accordingly in proper protective riding gear. In short I think you should only use you Bagster Tank Cover on cool or rainy days.

[Trekker]

I don't have a 1300.... but it seems to me something may have been pinched off. This just doesn't seem right. Maybe you need to check under the top cover?

[ST-Rider]

...at temps over 113 degrees F. When I got home the bike was making a gurgling sound from the gas tank. I slowly opened the gas cap and heard pressure releasing and then it spewed gas out of the filler neck like a geyser...When I first heard this Gurgling Noise in my '03ST, it was actually quite disconcerting. It being a brand new bike. In the quiet of my garage just after I'd turned the bike off after a ride in 100 degree F temp, I was exiting the garage when I heard the GN intruding on the normally silent garage. I opened the gas cap, with no spewing or pressure released thankfully, and actually saw the air bubbling in one spot in the tank. I assumed it was venting. The tank was pretty hot. It happened numerous times after that, and all I ever found was the bubbling and a hot tank. My '05ST also makes the GN when it's very hot. Never had a bit of trouble with either bikes. Neither tank has ever been too hot to touch, uncomfortable, yes, but not too hot to touch. BTW, knowing how hot my ST1300s get and got, using a tank bag in such high temps might inhibit heat dissipation from the tank. When it gets very hot outside, I keep a large floor fan blowing on my '05 when I turn it off after a ride. Helps cool it down pretty quickly. I don't worry about the GN, but if you do, you might want to get it checked out.

[Daryl]

A BLEVE between my legs! :o4: YIKES!!


Propane tank school (VFD) was exciting enough!

Mine gurgles as well on hotter days - but never had a geyser....

Matter of fact - I don't think I have ever opened the gas cap when "gurgles" where present unless I did it unknowingly while filling up??

[EagleSix]

...this might not help much because it is not an apple-for-apple....

I have a tank bag on my ZX-14. The ZX runs much hotter than the ST13. I haven't expereinced any adverse effects from the tank bag. I had a smaller tank bag on my ST13, but only used it occassionally during some pretty hot days, but again it didn't seem to cause in adverse effects.

.

[Rob Hephner]

OK, I have to ask......can you actually boil gasoline?

I mean something tells me that at that temp it would explode or something.....

[ST1300 Alicia]

Yes you can boil gasoline. Boil means to change state from a liquid to a gas. The old term vapor-lock refers to the fuel boiling in the fuel line where as the fuel quits acting like a liquid and takes on the properties of a gas. The Bagster tank cover our fellow rider is referring to is not a tank-bag but a complete cover made of a leather like material wrapped all around the tank. Completely insulating it from any heat exchange to the rider or to the ambient air. Hear in lies the problem, with continued heat build up in the tank it sounds like the fuel is starting to boil. Not a good thing! When he opens the gas cap the pressure is released and the fuel boils and sprays out.

[Rob Hephner]

Hmm, yea I didn't think of the true definition. LOL I was thinking of the rolling boil deal.

Yea, does not sound like a good deal.

[CruisingDog]

So what temp does '91 boil at ?

Extra marks for answering this one.... :-)

.....OK, assuming a 2x atmospheric pressure as a basis since boiling points depend on pressure.

[clmixon]

Hey, Guys,


I open my cap all the time with a tank bag in place and temps over 110 for more than 4 hours, I have never heard bubbling, seen any signs of overpressure or anything elese. I would suggest you check the vent line to your tank. It should never pressurize like that.

Besides, the gas in the fuel rail , right on the motor is not exhibiting this type of behavior or your bike would not run...it would be vapor locked.

Chris :06biker:

(No heat, no wobble, Just fun)

[EagleSix]

Yes you can boil gasoline. Boil means to change state from a liquid to a gas. The old term vapor-lock refers to the fuel boiling in the fuel line where as the fuel quits acting like a liquid and takes on the properties of a gas. The Bagster tank cover our fellow rider is referring to is not a tank-bag but a complete cover made of a leather like material wrapped all around the tank. Completely insulating it from any heat exchange to the rider or to the ambient air. Hear in lies the problem, with continued heat build up in the tank it sounds like the fuel is starting to boil. Not a good thing! When he opens the gas cap the pressure is released and the fuel boils and sprays out.

ALICIA....thanks for pointing out I misread his post about the tank cover as a tank bag, something I try not to do, but this one caught me!!!! Thanks Again.

.

[RibsST1300]

Boiling Point of Gasoline

Gasoline as used by vehicles is a mixture of roughly 230 different chemicals. Gasoline formulations vary depending upon the location, time of the year, environmental regulations, and availability. If the PEAC user looks up the boiling point of gasoline on the PEAC tool, the temperature 102o F (or 39o C) is displayed. But the information is misleading. Gasoline boils over a range of temperatures, with the most volatile components starting to boil away at roughly 102oF. The less-volatile components will boil at higher temperatures. Gasoline boils over range of temperatures, between 39 and 200o C (102oF and 392o F) typically, the temperature range varies depending upon the formulation. The final boiling point of the last residual of gasoline might be typically 225oC (437oF). This is in contrast to a pure chemical such as heptanes (one of the components of gasoline) which boils at a single temperature (209o F; 98oC).

Petroleum refining begins with the distillation of crude oil into fractions of different boiling ranges, usually called “light naphtha”, “heavy naphtha”, “kerosene”, “light gas oil”, “heavy gas oil”, and “reduced crude”. The naphtha fractions obtained by distillation are also called “virgin naphtha” or “straightrun gasoline”. The hydrocarbon products obtained by distillation depend greatly upon the type of crude oil being distilled. Kerosene and light gas oil fractions (also called middle distillates) are used in the production of kerosene, jet fuel, diesel fuel, and furnace oils. The heavy gas oil may be used for heavy diesel fuel, industrial fuel oil, and bunker fuel. All of these are mixtures of various hydrocarbon compounds with a range of boiling points. If the PEAC user looks up the boiling point for fuel oil, jet fuel, naphtha, or other petroleum distillate, a single temperature is displayed representing a temperature at the lower end of the boiling point range.

The lower boiling point hydrocarbon distillates are more valuable because they are major components of gasoline. A major petroleum refining step is hydrocracking, where higher boiling hydrocarbons are broken down or cracked forming lower boiling point hydrocarbons. The higher boiling point hydrocarbons are subjected to hydrogen and heat in the presence of a catalyst which results in the formation of lower molecular weight, lower boiling point hydrocarbons. The catalyst, which becomes fouled with carbon, is regenerated.

A typical breakdown of modern gasoline (excluding additives and oxygenated compounds) might be 15% n-paraffins (examples: pentane, hexane, heptane, octane, decane, etc.); 30% iso-paraffins (examples: 1-methylpropane, 2-methylbutane, 2,2,3-trimethylbutane, etc.); 12% cycloparaffins (example: cyclohexane, cyclopentane, etc.); 35% aromatics (examples: benzene, toluene, ethyl benzene, 1,3,5-trimethylbenzene; m-xylene, etc.); and 8% olefins (examples: 2-pentene, 2-methylbutene, cyclopentene, etc.). The octane number of the gasoline is a function of the components.

The U.S. Environmental Protection Agency has specified that gasoline contain a minimum of 2% oxygen by weight to reduce automotive emissions and improve air quality in polluted areas. This can be done by adding alcohols, notably ethanol, to gasoline to supply the oxygen component. Until recently, refiners have added methyl tert-butyl ether (MTBE) to gasoline to supply the oxygen component; a gasoline composition of 12% MTBE would meet the 2% oxygen by weight requirement. But MTBE proved to be a dangerous pollutant itself, contaminating groundwater from leaking gasoline tanks at fuel stations.

Modern refiners add detergents (usually an amide compound and alkylammonium dialkyl phosphate to prevent the formation of contaminants in the carburetor or fuel injectors. Light lubricants may be added to help lubricate cylinders and top piston rings. Deicing and anticorrosion additives are also in modern gasolines. Organic dyes are also added to identify brands and grades of gasoline.

In summary, gasoline is a mixture of many different chemicals. Many of the components of modern gasoline are also individually listed in the PEAC tool. The mixture boils over a temperature range rather than at a single temperature. .

Wow. Well said.

[Bigfish]

HUMMMPPHH! Boilin gas ....BAD! Me not ride, no wait, Me have popcorn to make! Me ride....yes!
Bigfish

[dteel]

Paul R. Buettner, wow, well said indeed. Extra points? Heck you pass without taking the test.

[CruisingDog]

Boiling Point of Gasoline

Gasoline as used by vehicles is a mixture of roughly 230 different chemicals. Gasoline formulations vary depending upon the location, time of the year, environmental regulations, and availability. If the PEAC user looks up the boiling point of gasoline on the PEAC tool, the temperature 102o F (or 39o C) is displayed. But the information is misleading. Gasoline boils over a range of temperatures, with the most volatile components starting to boil away at roughly 102oF. The less-volatile
.
[snip]
.
In summary, gasoline is a mixture of many different chemicals. Many of the components of modern gasoline are also individually listed in the PEAC tool. The mixture boils over a temperature range rather than at a single temperature. .

A++ for good contribution. B- for being a smart-arse!

So I guess we can say that the first boiling point of 91' gasolene is around 102 F ? This is probably what has been heard. Now what if you pressurize it ?