ORIGINAL: downunder
Although nitro can be a monopropellant it provides more heat energy when combined with oxygen and used as a fuel. This is why dragsters have a huge supercharger on them
. It's possible that in our engines some of the nitro might self-ignite but that's not its main purpose.
That is incorrect, as a monopropellent there is more fuel to burn, even if there is less energy per pound. The reason they have a supercharger is to compress the air, which allows an even richer mixture per volume, but less per pound. They cannot run as a monopropellent because it cannot be ignited with a spark and no air, and the hydrolock would break the engine. None of the nitro in our engines self ignite, detonation is caused by the more rapid flame front. After the flame front has traveled through the cylinder the fuel then actually burns more slowly than gas or methanol. However this is in part because of the rich mixture and lack of oxygen. In fact the fuel complets burning when it goes out the stack and comes in contact with air to burn off the partially burned fuel which is mostly unburned hydrogen, hydrogen oxide, carbon monoxide, and nitric acid.