Supplying Oxygen to Air Intake System

[replicant_008]

Actually, I have a business degree - the knowledge of pressure and gases comes from being a Master Scuba Diver and I've spent the past 10 years or so helping out various friends with karts, open-wheelers and other race cars. You learn a lot when building a car from the ground up and building the loom and electronics especially if you have data logging and laptop adjustable engine management.

[dericos]

Yes, I had a NOS system for my Miata. No, I didn't have the heart to install it after 3 years and sold it. Yes, I was a professional SCUBA diver ( which is really totally irrelevant here ).....

[ Not relevant to this discussion but should be good background ( for me at least )!
Let me get this straight?
Question 1) NOS drops the air temperature (which is always good!) AND increases O2 at the level of 33% O2 to 66% N2 ratio ( as opposed to 21% O2 to 79% N2 normally ) thereby increasing O2 which increases more fuel input ( by the reaction of the O2 sensors to increased O2 in the exhaust).....? IS THIS CORRECT? Q1(
Question 2) NOS breaks up into it's elemental parts ( N20 ) during the heat of combustion? Q2(
Question 3) NOS is inert until it breaks up into it's elements during the heat of combustion? Q3(
]

I think the increased flammability issue mentioned above by SaabJohan pretty much answered my questions about adding pure O2 instead of NOS to the air intake! (That might be a deal breaker to me, as the O2 tank would be in the trunk with my battery ( enclosed space 4 foot away !!! ) and above the gas tank!!!!)

But as I did come here with pretty much the same question as Athiril... just a lil O2 boost as per a NOS system..... he last mentioned 25% O2 mixture.....?

Question 4) The effects and problems of adding a little bit of oxygen to raise the percentage to 25-30% oxygen mixture ( as per a NOS system)? Q4(

Question 5) Would the increased flammability issue negate a consumer application here? Q5(

and.... since we are not talking about running a pure O2 intake as with a torpedo nor a pure Oxygen underwater breathing aparatus let's stay on topic.....

(Flame me if you want but 5 questions on the table here)
TY Gentlemen!

[curtis73]

Normally, I would close this thread (its a no-no to revive threads from 2004) but you ask some good questions. I'll leave it open for now.

Originally Posted by dericos

Question 1) NOS drops the air temperature (which is always good!) AND increases O2 at the level of 33% O2 to 66% N2 ratio ( as opposed to 21% O2 to 79% N2 normally ) thereby increasing O2 which increases more fuel input ( by the reaction of the O2 sensors to increased O2 in the exhaust).....? IS THIS CORRECT?

Correct. If 10% of your intake charge is N2O, and N2O and atmospheric air are 33% and 21% respectively, it will increase the percentage of oxygen by 10% of the difference... basically make it 22.2% oxygen.

Question 2) NOS breaks up into it's elemental parts ( N20 ) during the heat of combustion?

Correct. The majority of it disassociates during compression, the rest disassociates as combustion spreads across the chamber.

Question 3) NOS is inert until it breaks up into it's elements during the heat of combustion?

Correct again. It is categorized as a non-flammable gas

I think the increased flammability issue mentioned above by SaabJohan pretty much answered my questions about adding pure O2 instead of NOS to the air intake! (That might be a deal breaker to me, as the O2 tank would be in the trunk with my battery ( enclosed space 4 foot away !!! ) and above the gas tank!!!!)

Agreed. The amount of pure oxygen you could inject is extremely limited which is why N2O is such a common choice. It provides you with the same O2 enrichment in a safer package.

Pure O2 will not burn, but it makes darn near anything around it practically explosive. Cast iron will burn in the presence of pure oxygen, so one little backfire through the carb could cause catastrophic damage to you, the car, bystanders in a 1/4 mile radius, and could rip a hole in the space-time continuum. I learned that on Star Trek, so it has to be true.

Question 4) The effects and problems of adding a little bit of oxygen to raise the percentage to 25-30% oxygen mixture ( as per a NOS system)?

You would lack the stability of the N2O compound. If you had (for instance) a mixture of oxygen and an inert gas like Argon, the oxygen is free and available for combustion all the time. N2O remains inert until its in the combustion chamber. See space-time continuum comment above

Question 5) Would the increased flammability issue negate a consumer application here?

Yup. We're talking insane levels of flammability. Like dynamite levels. One little backfire, spark, oxygen leak, anything, and you're looking at instant death. There might be nothing left of you except some ashy bone fragments.

[wicker7]

I too have been thinking of adding pure oxygen to the intake of my 4.0 6cylinder jeep Wrangler. At 11 mpg I need help quick. My plan is to start with a mpg meter and an oxygen flow meter so I can slowly add the small volume of oxygen to the intake. According to my calculations, I should be able to add to the existing atmosphere intake, up to 20 cfms of oxygen at 2000 rpms which is about 70 mph. this would increase the oxygen by about 5%. This is not for racing only normal driving conditions, so of course at slower speeds there would be less volume of oxygen to keep the same 5% increase. Also, I have been using oxygen in welding for 35+ years and don't understand the inordinate fear of using oxygen. I haven't seen anyone blow up. I did start a fire one time in a field with a cutting torch but thats why you have a fire extinguisher on hand.

[Moppie]

How do the plan to introduce the O2 to the inlet?

The danger comes from how you do that.

[jdmccright]

O2 and flammability? Google "Apollo 1" and read on what happens to substances immersed in a pure oxygen atmosphere.

Using oxygen for welding is one thing...you want a hot, clean burning oxyacetylene flame. Driving around with a pressurized bottle of pure O2 to feed into the carb is overkill IMO. From an economical stand point, I don't see how bumping the O2 level will decrease how much you spend per mile.

The misconception here isn't trying to achieve higher MPGs, which you might succeed in doing. But the cost of that O2 bottle has to be added to the cost of the gasoline burned over the miles driven to get the real cost per mile.

For example, a car getting 30 MPG costs about $0.117/mile when a gallon costs $3.50. By comparison, your 11-MPG Jeep costs you $0.318/mile.

Disregarding the costs to install such in injection system and the cost of purchasing the bottles for refill, the cost of a bottle of O2 gas has to be spread out over the number of miles driven. Now, I have no clue on what the price should be for a reasonable size refill, let's say $100. And I'd have to do some serious calc to figure out how long a cylinder would last at a certain CFM of flow for your engine. So for simplicity sake a bottle lasts one tank.

Your Jeep has about a 20-gallon tank, giving you a current range of 220 miles. Lets say with O2 injection you bump that to 13 MPG...YAY, right? Not quite.

With 13 MPG you'll go 260 miles, but you've spent $70 on gas and $100 on O2, resulting in a cost of $0.654/mile. That's not saving. If the bottle lasted 5 tanks, that's still an added $20 of oxygen you've used...$0.346/mile, though closer to your break-even point.

With this in mind, I'd suggest spending the money on finding out why you get such horrible MPG in the first place. You don't mention a specific model, year, 2WD/4WD, etc., but you should be getting 16-22 MPG for a 4-L Cherokee. To get 11, there is something very wrong.

Hope this helps and good luck!

[Black Lotus]

Originally Posted by wicker7

I too have been thinking of adding pure oxygen to the intake of my 4.0 6cylinder jeep Wrangler.

We have pictures at work of an older airplane (727) in South America where the airlines maintenence facilities decided they wanted to modify a gaseous passenger oxygen system, which runs at 1850 PSI. When they finished their work, the mechanic opened a cylinder to the system and promptly burnt a 3 ft diameter hole in the side of the airplane. All the stainless steel tubes in the area went missing as well. I imagine the individual who opened the shutoff valve saw spots for about a week.
Amazing what will happen when you don't use "oxygen clean" techniques in the fabrication and preparation of the tubes.
As far as I know, the airplane is still in a corner of the airfield, occupied by the local jungle bats.
Any speck of dust, any spot of grease, anything that is combustable in the tube or oxygen rated flexhose can start a fire.
Further, when opening the valve on a cylinder charged up to full pressure, a pressure wave will travel down the tube and, if encountering any dead end, will heat the tube up locally, possibly causing a fire in the area as well.
There are ways to deal with this, but it's none of your business.....
So, don't even think about it.
Liquid oxygen (LOX) is even cooler. Get a leak anywhere, and if it runs out onto the tarmac you can have a friendly little blaze right there on the pavement.
Gaseous oxygen and LOX is actually pretty safe, you just have to know your business when designing and servicing it.
But if you miss one step, you can burn your vehicle to the ground.
Or lets just say it will burn out of control until the oxygen in the cylinder runs out.

[wicker7]

Great info, thanks. It is all in my mind at present. I thought I said earlier it was a Wrangler, 4x4, 33" tires, 6 cylinder. That is partially the reason for the bad mileage. Anyway safety first, you can be sure I will not burn my Jeep or the city to the ground. I may just switch it over to diesel which would present a totally different set of problems. It just pisses me off that cars don't get 100-200 mpg. Hybrids are a joke at 50 mpg. My system would be no different than NO2 except I would not replace the atmospheric intake, but only add a small amount of oxygen starting at 0. the reason no2 has to replace atmosphere is because it is already mixed.2/3 is inert gas, I can get 78% nitrogen breathing. Like I said it is all in my head now and at the volumn I'm talking about it may not be feasible, possible, but not cost effective. Thanks again, so far this is the only site that even mentioned the subject.