Thread: Liquid Oxygen

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They have to have those tight valves you speak of for all those fuel cell folks

So u propose selling fuel in those like coleman propane cylenders?

Hey i like that idea just stop at wallmart get some coleman cylinders and screw em right in!!U could have a row of em in the trunk !I like the propane thing to begin with u can go like 800 miles with the stuff on 1 fill!{{{need to find out more about this propane}}}

propane is still pretty cheap here, now there is a good idea !!

Hi guys! Did you miss me? Anyway, ive been reading up on the last two threads, and i have been thinking, what if you had dual injectors for each cylinder. Use a direct-rail system for each strip, and injected oxyogen by one and propane by the other? or hydrogen, but im not as big on that due to the molecular size. As the computer would automaticaly sense the amount of oxyogen being left out due to current o2 sensors, you could re-calibrate the system, get a really clean burn, get fairly good mileage and have a low-emmision system at high timing. I know this seems simplistic, so whos going to tell me whats wrong with it? Streets, Tech, Don, heres looking at you

No streets, im looking for a scientific analysis from someone I can actually respect. Not a troll who doesnt give advice and just badmouths. And yes, i was gone :P

Drg84: I went back and reread page 1 of this thread to try to remember how it started. Evidently the intent is to use pure oxygen for more performance. My position is that it is not necessary to use LIQUID oxygen and associated cryogenic (cold) problems if one merely uses more oxygen in the incoming gas intake. I see no problem using an added rail to permit a higher percentage of oxygen in the "air" since normally air is about 19% oxygen and 79% nitrogen and using ambient temperature oxygen from a bottle. I would want to examine the nozzle system used in the fork lift tractors before including a second input of propane even though propane is probably easier to regulate than hydrogen. One other factor is that while propane may act like high octane fuel in the sense that it burns smoother rather than detonating, that does not mean the heat energy generated is equal to any of the several isomers of octane with 8 C atoms in octane but only 3 C atoms in propane. It is similar to the use of methyl alcohol in race cars where the jets/injector nozzles have to deliver much more liquid and then there is only one C atom in methanol to burn anyway. You can use higher C.R. with methanol and it will run cooler, BUT you will have to use a lot more methanol than octane to get the same power. Thus the jetting or injection volume would have to be worked out based on the heat energy released as well as the burning rate. The octane rating depends more on burning slowly, ie rate of reaction, than the actual energy released. Thus the standard of branched octane as a chain of 5 C atoms with 3 C atoms on the side burns more slowly than the same number of 8 C atoms arranged in a straight row which burns faster like a fuse. They both give off essentially the same amount of heat energy, but the branched octane burns more slowly relative to the slower mechanical processes in the engine. Chemical reactions can be much much faster than the time it takes for a full four cycles in an internal combustion engine so the main function of octane and octane boosters is to SLOW DOWN the reaction to match the chemical speed of events more closely to the mechanical events. Detonation is BAD because it is too fast for the engine! Thus if you are willing to risk blowing up an engine or at least burning valves in an engine you could just try using richer jetting with ordinary racing gas and a flow of pure oxygen from something like a NOS carb plate. I expect the amount of pure gas oxygen at 25 degrees C would not need to be much to support combustion of more liquid fuel of the ordinary kind and there would be no need to go to propane. If propane is substituted for the liquid fuel then the metering from the jets/nozzles has to be worked out from balancing the reaction:

CnH2n+2 + ((3n+1)/2) O2 -> n CO2 + (n+1)H2O + heat

I do not want to accept responsibility for you blowing up your engine or burning the valves in your engine, but you are right in saying that the present day oxygen sensors could be used somewhere in the fuel stream with an onboard computer to exactly tune the fuel-oxygen ratio for optimum complete combustion. One simpler way to do this might (???) be to deliberately set your nozzles/carb jets too rich by a certain amount and then increase the oxygen flow a small amount and then look at the plugs for a rough estimate of the right mixture. Sooty plugs would mean not enough oxygen for that amount of fuel so the oxygen should be increased. By trial and error this could slowly be used to develop a feeling for how much additional fuel a given engine could handle before exploding or burning valves. If you continue to enrich the amount of incoming fuel more than the amount of oxygen you could always approach the optimum oxygen flow from the fuel rich side and avoid burning valves. I think some form of dynanometer would be very helpful in seeing how much fuel and oxygen you could add before you get mechanical failure. In a way you would be doing what a supercharger does in a much easier way without the mechanical energy losses of either a positive displacement or centrifugal turbocharger. However there would be a limit to how far you could take this in the sense that without a positive pressure all you can do is displace the nitrogen in air (79%) by pure oxygen so the maximum increase would be about a factor of four (4) compared to the usual 19% of oxygen in air at one atmosphere (at sea level). On the other hand this could push a nominal 300 H.P. engine to about 1200 H.P. and surely there would have to be a lot of mechanical improvements to handle the mechanical stress of the added power. What I am saying is by that using pure oxygen gas at 25 degrees C in the inlet and increasing the amount of fuel added to the intake one could have a similar effect to a supercharger. If you want to try it let me know how it works but please do not hold me responsible for what happens to your engine. Of course if you want to invite me as a special guest to the end-of-season awards dinner when you receive the championship in whatever class they put you (Top Fuel ???) I will be glad to attend with you! One last word of caution is that it is surely not practical for street driving and so does not solve the problem of a future gasoline shortage but would only be a replacement for present NOS systems. However, we already know that NOS can lead to engine damage and fire as well as more power, so why not just use NOS systems that are already well developed. The ONLY reason I can think of to justify using pure oxygen instead of nitrous oxide is that in the final analysis pure oxygen can bring in more oxygen than nitrous oxide. BUT (!!) isn't the use of a NOS system already at the stage of dangerous adventure? Unless there is some elephant motor out there that can handle the added horsepower of pure oxygen you might as well stay with present NOS systems because it is already easy to damage an engine that way. Maybe HEAD actully "stumbled" onto an interesting idea, but I do not have the funds or the dyno to experiment with pure oxygen instead of nitrous oxide. If there is a sufficiently strong block/engine parts, Top Fuel times might be available with pure oxygen instead of using nitrous oxide or supercharger pressure. Well it is an interesting topic anyway.

Don Shillady
Retired Scientist/teen rodder

Thanks Don, that is what i was looking for. You are right that it doesnt nessicarily have to be injected liquid oxyogen, but there is some food for thought here. I have an idea of a motor that could take a lot of the abuse of this combonation, and that would be a multi-port 350N olds motor. Needless to say, this would be a severe modification, but it could be done. I do agree with the NOS-O2 similairities, but only to a certain extent. You have to consider that with NOS, you are running the secondary "Boost" through the intake and relying on vacum. with the injection, you can use the injection in order to controll the amount of damage by regualting the timing. Now i dont plan to do this any time soon(19+underpaid=broke!) but its a good thing to research on. Oxyogen may be a possible accelerant due to the ability to fuse with most fuels, but it makes you wonder-what else can be an alternative? What would happen if you were to combine two compleltly different fuels in a cylinder instead of fuel/oxyogen? This is gonna be an interesting week of though. Thanks.

Drg84:

Nineteen is a great age but with a lot of important things to sort out. I recall daydreaming a lot about sectioning a '50 Ford shoebox and how I might do it at age 19, but now I know that would have been an overwhelming project for a first attempt. Still such ideas can stay with you for a lifetime when one has the "car hobby sickness". One thing I should have mentioned above is that since the NOS gas nitrous oxide gas has the formula NNO even if you forced the intake to breathe in only 100% NNO you would in effect be increasing the oxygen content to 50% compared to the usual 19% in air and of course that would be a very "heavy load" of nitrous oxide, far more than is usually used. Then if one used an intake which only had pure oxygen from something like a fast flow oxygen tent the intake gas would be 100% oxygen so this would exceed the conditions from the maximum amount of oxygen from pure NNO. In a practical sense the new way would only be used if someone actually used it successfully as when the first Chrysler hemi engines were used in spite of their higher weight at a time when OHV engines were beginning to dominate traditional Ford flatheads. At that time it was not clear whether Olds, Chevy or even Ford Y-block engines would be the new technology in the late '50s. Of course if HEADS actually built an "oxygen engine" and started to win, there would be a lot of folks copying the idea. Another thing to think about is that U.S. Armed Service Research Labs are always looking for compounds containing C, H, N and O which lead as directly as possible to CO2, H2O and minimal amounts of NOx. The formulas of most explosive compounds often have ratios of atoms close to these products. Nitromethane is in that sense a form of liquid dynamite when used as a fuel additive. Anyway I will focus for now on completing my low rpm torque motor but I wil try to answer chemical questions when I can in return for excellent technical comments from experienced mechanics, particularly for SBC.

Don Shillady
Retired Scientist/teen rodder

Don,
I always thought about using pure o2 instead of NOS injected and wondered why O2 wasn't used. I would think it's because pure O2 in the presence of a hydrocarbon can ignite very easily. So I would think if you added the pure o2 to the intake charge you would probably blow the intake off of the car?
Not sure of this but seems like it could happen.
I work with pure O2 in gas form at 600 psi. We have to use cloth gloves and special cleaning fluid just to install gaskets in the piping. We have to clean all of the gaskets and flanges with teh fluid and then blacklight the fittings to insure there are no oils left. There have been instances of spontanous fires resulting just from body oils left on the gaskets from someone's fingers. I wouldn't want to be adding the stuff to my engine, just too reactive with about anything for me.
Don C