Supplying Oxygen to Air Intake System

[Athiril]

Hypothetical performance question
What would happen if i supply oxygen to the air intake system in the car that goes to get mixed into the fuel mixture? What would happen if i accidentally supplied Hydrogen instead? would the oxygen be safe in small amounts? and would it have any benefits?

[SaabJohan]

Pure oxygen is reactive with several materials, in other words it's very dangerous to supply it to the intake system of a car. When oxygen content increase combustion speed and temperature will increase. With 30-40% oxygen we will have such high temps and pressures that the engine can't withstand it.

Hydrogen is a fuel and will be burned like any other fuel, it's properties are however different and it will therefore require a different fueling. For example BMW have hydrogen fueled four-stroke engines.

[454Casull]

It would be very expensive and dangerous to use pure oxygen as the oxidiser in an engine. The injection of a small amount, however, is fine if your fuel system can handle it (that's what nitrous does, anyway).

[Athiril]

The air mixture from the atmosphere is like 21% oxygen and 78% nitrogen, and 1% misc, i was going to like add a little extra oxygen into the air filter, so i get a mixture of like 25% oxygen, and 74% nitrogen, etc, but still have the same amount of air flowing through the air filter, say 1000kg of air an hour before i put extra oxygen in, and 1000kg of air after i add the extra oxygen in.

[Athiril]

btw: my car is an R30 Skyline, 2.4Litre L24(E) engine, 6 cylinder

[Porsche]

How much oxygen would be required? I think it would simply be impractical to have to set up a system (tank most importantly) that could feed enoguh oxygen to make a significant, and not harmful gain.

[replicant_008]

This all depends on the application.

If you have an enhanced air diving licence you can obtain EANx 34 (34% oxy and 66% nitrogen).

An average dive tank at 216 bar (Yep over two hundred bar) or 3,240 psi holds about 80 cubic feet.

Just for arguments sake because I don't know the stats for a L24 - but at say 450cfm max - even if you get the whole contents of the tank out of the valve (unlikely) you'd deplete the contents of the tank in less than 11 seconds. With two tanks aboard you'd be lucky to get a quarter mile run.

[SaabJohan]

Do we have a new winner of the darwin award perhaps?

Pure oxygen is quite cheap, but remember that it reacts with several materials. It's enough that the feeding lines are contaminated (plumbing must be oxygen safe and cleaned with acetone). What happends then if the pure O2 comes in contact with oil/fuel in the intake?

Remember that N2O is inert before the compression phase where it separate, O2 isn't.

[replicant_008]

Correct SJ. Even on EANx36 most of the gear needs to be serviced to Oxy Standards because of the nature of the mixing process may result in exposure to pure oxygen.

My point is that given the volume required say at 450 cfm using only EANx 36 which contains 70% more oxygen than regular air you'd have immense difficulty containing and delivering enough to make a difference - assuming you'd even do a quarter you still have issues getting the contents of 160 cu ft of air out of two dive tanks in less than 20 seconds...

[Porsche]

Wait, are your calculations based on feeding the oxygen all by itself, or the oxygen with all the other air? 450cfm, is an awful lot of extra air to be adding just to boost the oxygen content by a few percent, I would think that 160 cft would get you a lot more than a 1/4 mile, unless everything you said is based around the idea of that much oxygen needing to be added just to boost the percentage from 21% to 25% what is the flow rate of the L24?

Oops, jsut read the bit about the 70% more oxygen content, does that not mean you've based everytihng around a 91% oxygen mix?

Hmmm, even if it did work, like the Hydrogen powered cars (some fo the earlier ones) anything at 216 bar isn't goign to like getting hit, it would definately be illegal given the pressures, which are hardly adequate at that.

[Athiril]

I was intending to add extra oxygen into the existing air mix going through the air intake system, not supply all the air on my own, I would only need to supply a little of oxygen to raise the percentage to 25% oxygen mixture, i dont know the flow rate of the L24E, but I was going to use an EGO and put a little bit in at a time to see the results on the EGO, which means I wouldn't need heavy equipment and an oxygen tank that would get depleted in seconds as people keep telling me, I already said in my second post to add oxygen to existing air, not blast a whole tank of oxygen through in seconds.

[replicant_008]

To clarify a few points:

- Regular air is 20.9% oxygen and the rest is mainly nitrogen
- EANx 36 is 36% oxygen and 64% nitrogen. This is a blend generally made from pure oxygen and nitrogen. 36/21 = 171.4% ie 71% more. If this was fed at 1 bar ie normal air pressure you'd effectively introduce enough oxygen to be equivalent to 1.7 bar of boost.
- 450 cfm was a guess based on the maximum flow rate of a twin throat Weber Carb for a medium displacement in-line six. I made a rough assumption based on full throttle and max revs to illustrate the high quantity of air required and also the difficulty in getting this out of two dive tanks in the time required. Even at 160 cfm you'd get a minute but you still have issues in getting this out of the cylinders and still regulate it down from a peak of 216 bar down to 1 bar.

[454Casull]

0 bar is generally considered to be ambient pressure, right?

[replicant_008]

At sea level - the mean atmospheric pressure is 1 bar - 1 bar of boost would mean that the total intake manifold pressure would be 2 bar (1 bar ambient + 1 bar boost).

For interest's sake, for every 10 metres you descend underwater at sealevel the pressure increases by 1 bar - so at 40 metres the pressure is 5 bar (or 4 bar more than at sea level). And you should see what that can do to an egg...

[Porsche]

Jesus, that means that Alvin would have to have withstood some..... 400 or so bar of pressure, that's 6000 psi... If I did everything. That's significant.

BTW, you are clearly an engineer of some sort, where did you acquire all this technical knowledge?