How to find the efficiency of a modified engine?

A modern, computer-controlled, multi-port fuel-injected engine is already matching the fuel charge to the available oxygen in the air charge. Combustion is already at nearly 100% in order to meet government mileage and emission requirements. The charge of pure oxygen would certainly allow a greater fuel charge to be burnt, but that is what a nitrous system is all about - it results in a great increase in power, but no real change in efficiency. The inefficiency in an IC engine is mainly due to the great amount of energy converted to waste heat, rather than mechanical energy (much like the great amount of heat rather than light generated by incandescent bulbs).

You seem to be the only poster with any knowledge and good sense about the mixing of pure oxygen and anything flammable. I rate your post as good.

What you actually get is a very severe explosion and fire and probably nothing left standing for several 100 meters, plus an awful lot of heavy stuff doing crash landings for even further distances.....for several minutes after the bang, some of the bits may have been part of your body up to very recently....

NEVER EVER EVEN DREAM OF DOING THIS AS THERE IS NO ADVANTAGE ANYWAY, the energy cost of the Oxygen is far more than the extra energy gained...losses as always.

If you want to see a way to get more out of an IC engine with less fuel, then look at Wikipedia and find 6 stroke engines. They run cool enough to put your hand on, need no cooling equipment and appear to be very fuel efficient.

The Crower appears to be a particularly good version and he also has a simple website to visit....check this link out by clicking on it:-

Six stroke engine

Crower six stroke

Any free oxygen left in the engine after combustion of the fuel will corrode the engine parts, especially the outlet valves.

I would propose that pure oxygen be used very carefully as it could have severe side effects like explosion with oil or other chemicals in the engine.

Since O2 makes up about 21% of the air normally used, you would (in principle) be able to burn (100%/21%) 4.76 times more fuel per power stroke.

But I'd guess that adding anything like that amount of extra fuel will reduce the efficiency greatly. As well as (many) other things the pressure-temp during combustion versus the pressure-temp at the end of the power stroke will have been adjusted during the design and testing cycle to maximise the motor's efficiency.

Still it looks like a fun project, good luck. ffeJ

I may be a bit sensitive, but why would this be considered off topic? ffeJ

I guess its because you (and many others) did not include in your post a warning about the explosive effects of pure oxygen when brought near anything remotely flammable!!

We try to be as FULLY accurate as possible so that none of the original questioners/posters ends up on the Darwin awards page. See link for further details.

You simply forgot!!

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O2 is an oxidizer and to get it around petroleum products, you're asking for trouble (read BIG BANG when it oxidizes with the product). Nitrous used in engines has a good bit of oxygen but not pure oxygen. It works by the amount of O2 in the nitrous is more to burn but additional fuel has to be added or it will run lean and burn up the engine. Putting extra O2 into the engine will not increase the efficiency of it. The efficiency of it is determined by the amount of fuel put in and it's BTU content vs. the engine output in HP. You're not going to get much better than what came from the factory in a computer controlled car. There are things you can do that may increase it a couple of percent but that's going to be about it.

You seem to confuse efficiency and power.

Adding any amount of Oxygen will not improve efficiency. It will not even make any noticeable increase in power, unless more fuel is added to the system. There is a certain and FIXED ratio between the amount of fuel and air that will give you the Ideal mixture. This ratio about 1:15, 1 part of fuel to 15 parts of air ( petrol or gas engines),when changed, will cause a lean or reach mixture. If more fuel is added without any more air it will simply not burn and will evaporate in the exhaust pipe, or may even explode there. (Backfire) If more Oxygen, or air for that matter is added the mixture will become lean, and at best will cause engine heat to rise. By adding pure Oxygen, you are also subjecting the engine to a possibility of oil/Oxygen mixture which is highly explosive, and very very dangerous. In addition free O2, is very aggressive, and highly corrosive to almost all metals, so you are looking now at a whole new set of problems.

Summery: you get nothing but problems, without any added value. Better scrap the idea.

Hope this helps.

Wangito.

It won't increase the percentage of fuel combusted. In a lean-burn engine, all of it is combusted anyway.

Increasing the oxygen concentration above ambient will reduce the amount of hot nitrogen leaving in the exhaust and increasing the fuel supply in concurrence will increase the available engine output power, up to a limit. Excess of oxygen in some combustion processes generates enough concentrated heat to cut metal. And if the engine block is made of metal that's bad news for the longevity of the engine; one is making a bomb. Plus, some parts of the engine may not be able to withstand the extra torque and speed. All in all it's a good recipe for saying "bye-bye engine".