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Fuel storage Question for Rich

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Posted by: MXN4FUN

I am running VP MR#2 and have purchased a 35 gal drum. I have the ability to either pull a vacuum to get an air free enviroment inside the drum or charge with nitrogen to diplace air. Which would be better? I use the drum up in about two months. Is this even necessary?


Posted by: Rich Rohrich

Pressure with nitrogen is the better plan and it makes it tougher for the MTBE in the fuel to boil off. Is it worth it YES, just be careful not to over-pressurize and split a seam in the drum http://dirtrider.net/ubb2/smile.gif


Posted by: MXN4FUN

Thank you for the advice Rich. What would be a good pressure as I have a gauge hooked up. Thanx in advance.


Posted by: Rich Rohrich

I've seen a few people use about 7 psi with excellent results. I'll be talking to the regional Phillips distributor Dr. Dave Redzsus at Precision Automotive Research so I'll ask him for his recommendation.




Posted by: motopuffs

Isn't the main goal to displace air? If this is true, once you get the air out, zero pressure (atmospheric) would be fine.

What is the vapor pressure of MTBE? Sounds to me like keeping the drum as cool as possible would help. With the nitrogen in the drum, condensation shouldn't be possible.

Some folks have an extra fridge for beer, others....

[This message has been edited by kookooformotopuffs (edited 04-01-2001).]


Posted by: spanky250

I would think a vaccuum would be the worst thing you could do, as this would force the evaporation of the more volitile elements in the fuel. A vaccuum lowers the boiling point of fluids tremendously, you can make water boil at room temperature with a 2500 micron vaccuum.


Posted by: Mac

Water will actually freeze in a vacuum.

Mac
00-KDX-200


Posted by: Rumpelstiltskin

What sort of processes are going on that cause fuel to become less desirable over time?


Posted by: bwalker

Race gas is made up of various compounds that have different boiling points. These compounds are some times referred to as light and heavy ends. Light ends have low e boiling points and heavy ends have high boiling points. The idea behind pressurizing the drum is to keep the light ends from evaporating. If your fuels light ends are gone so is your bike throttle response. When you add MTBE to the mix storage becomes even more crucial as MTBE has a very low boiling point. Lose the MTBE content in the fuel and your jetting will be rich. All of the above mentioned problems tend to through a wrench in the tuneing process.

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Ben Walker
00 cr 250
BRC,AMA,NRA Member


Posted by: motopuffs

If an increase in pressure raises the boiling point (and it does), than it also should raise the freezing point.

A decrease in pressure (such as a vacuum)would do the opposite.

I run plain old Amocco Ultimate (although I have used race fuel in the past) in my 01 CR250, and it has awesome throttle response, even with less than optimal jetting.

I truly believe that 90% of the people running race fuel don't need it. Just my opinion. But, I still enjoy reading and learning about it.




Posted by: spanky250

Quote:
Originally posted by Mac:
Water will actually freeze in a vacuum.

Mac
00-KDX-200

I have worked in the refrigeration industry for 17 years. The best way to remove moisture from a refrigeration system is to put the system in a deep vacuum, below 500 microns. The water will simply boil, and can be pulled right out with the vacuum pump. Water does NOT freeze in the approximation of a vaccum that we are capable of achieving without extremely expensive and complex equipment. With the proper equipment and controlled conditions, you can reach a state of near-perfect vaccuum, at which point water will both freeze and boil at the same time.



Posted by: Rich Rohrich

Quote:
Originally posted by spanky250:
With the proper equipment and controlled conditions, you can reach a state of near-perfect vaccuum, at which point water will both freeze and boil at the same time.


That state is called the Triple Point. The triple point of water is the temperature and pressure where water can coexist in all three phases (solid, liquid and gas) in equilibrium. Specifically the triple point of water is 273.16 K at 611.2 Pa.

Pretty cool stuff http://dirtrider.net/ubb2/smile.gif




Posted by: motopuffs

Would the freezing be due to the loss of heat energy from the boiling (expansion)?




Posted by: spanky250

Rich is right, it is called the triple point. This property is unique to water. I believe you are right about the cause of the freezing, but unfortunately I didn't pay as much attention as I should have in class. http://dirtrider.net/ubb2/wink.gif

Rich, I have read so many posts of yours that exhibit so much knowledge over such a broad range of topics, I am very curious. What is your occupation?

[This message has been edited by spanky250 (edited 04-02-2001).]


Posted by: dirt bike dave

Spanky - if he tells you, he will have to kill you http://dirtrider.net/ubb2/wink.gif


Posted by: Mac

Quote:

I have worked in the refrigeration industry for 17 years. The best way to remove moisture from a refrigeration system is to put the system in a deep vacuum, below 500 microns. The water will simply boil, and can be pulled right out with the vacuum pump. Water does NOT freeze in the approximation of a vaccum that we are capable of achieving without extremely expensive and complex equipment. With the proper equipment and controlled conditions, you can reach a state of near-perfect vaccuum, at which point water will both freeze and boil at the same time.


We always called it "outgassing" but now that I think about it I guess we are actually lowering the boiling point. I thought the High vacuum chamber was pulling the vapor out of the water using vacuum forces but you say it is boiling? I guess this makes sense. Its a pretty cool thing to see!! Our vacuum pumps dont like it very much though.

Mac
00-KDX-200

[This message has been edited by Mac (edited 04-03-2001).]

[This message has been edited by Mac (edited 04-03-2001).]


Posted by: TexKDX

Quote:
Originally posted by kookooformotopuffs:
I truly believe that 90% of the people running race fuel don't need it. Just my opinion. But, I still enjoy reading and learning about it.


Yea, they are better off spending the money on pipes, rad valves, and stickers, right?

Rich says jetting and fuel make the biggest performance and ridability gains on the modern fast bikes. I'll take his word for it.




Posted by: Rich Rohrich

Quote:
Originally posted by spanky250:
Rich, I have read so many posts of yours that exhibit so much knowledge over such a broad range of topics, I am very curious. What is your occupation?


I've had a lot of different jobs but up until a week ago I was an Applications/Test Engineer at 3Com. Now I'm just one of the many casualties of high tech downsizing http://dirtrider.net/ubb2/smile.gif
Maybe I'll take another low paying job in the motorcycle business, or spend my days debunking stupid myths that Jody and that nitwit Tim Olson start. NAHHHH, That would take to much time. LOL




Posted by: High Lord Gomer

After I win the lottery Rich is going to be my public relations manager. http://dirtrider.net/ubb2/tongue.gif

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Posted by: motopuffs

Tex KDX, if you personally find that race gas is the best option in your bike, more power to ya!

I'm just going off of my experiences with several bikes, and what I have read.

Jetting is critical, no arguments there!!!

But if you have no knock or ping and have a stable source of fresh 92+ octane fuel, it has been my experience that the improvement is negligible (using race fuel), and it is actually possible to take a step backwards with higher octane than you need. I could, however, easily be convinced that race fuel promotes better smelling exhaust...

For me it's a convenience and a cost issue, the closest race fuel is 25 minutes away, while the amoco station is just down the street.

I ran 50/50 in my 125 because I felt I had to have it jetted on the ragged edge to extract every last possible hp, plus the head was milled.

Anyway, I wasn't trying to tell you what to do, TEX, just making another one of my sweeping generalizations, but I still stand behind it anyway...




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Posted by: KawieKX125

Another interesting property of water/ice[ice in this example]:As you put pressure on ice, it melts, that is why it is slippery. i would have thought it would get "harder" under pressure, but it melts. Water is real cool. I love the stuff.

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Aaron's web site


Posted by: motopuffs

Wow, I never thought about that. So if my sidewalk was covered with frozen Mercury, for example, it wouldn't be as slippery?

I think sometimes friction and heat from pressure in a local area tends to also contribute to the lubricity of ice.

How about a bearing made of ice?

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Posted by: KawieKX125

Water is just really wierd. I found this out when I proposed an idea in chem class to make a freezer thawt used alot of pressure to raise the freezing point of water so much, it froze, but the teacher told me it would just get "wetter" because of this reason.

------------------
Aaron's web site


Posted by: spanky250

Kawie, the reason behind this is simple. You already know that raising the pressure of water increases the boiling point, right? It also lowers the freezing point. This is why the pipes in your house don't freeze at 32F. It usually has to get into the mid 20's before freezing pipes becomes a problem, depending on how much water pressure you have in the lines.

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1992 KDX 250-FMF porting,two-stage power reeds, Fatty pipe, Power Core silencer,titanium rod,Wiseco Ultra-lite, Pro-Action suspension...Oh my Gawd, they killed Kenny!


Posted by: KawieKX125

Normally, raising the pressure increases BOTH the boiling and freezing points. We just went over this in chem last week. Think of it like this, when the increased pressure acts on the water molecules, it creates more intermolecular forces to hold the molecules together. Then, it takes less energy to freeze it.
BTW, I was asking my chem teacher more about triple points, and she said that she though every element had one. Freaky.

Rich, my friends and I are planning to buy a 55 gallon drum of race fuel for cost reasons(it is really expensive in our area). We will probably get C-12 or MR2 and it will be used in about 3-4 weeks. Is this okay or is that too long? What do you expect it to cost? Also, where can I get sonoco, powermist, exxon, etc race fuels? I was thinking that I may be able to ge4t them cheaper if they are closer.

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Aaron's web site



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