Mopar Action On-line – Tech Questions
kieffer davis, Bartlesville, OK, 68 Dodge Dart 6 cyl
Why is nitrous used rather than pure oxygen?
Kief, I had to defer, and pass this one along to our resident rocket scientist, Mark Grubelich. Here’s what he had to say:
“The big boom, that’s why!
1) Pure O2 tends to sponatnousely ignite hydrocarbons…the greasy rag thing and the O2 tank.
2) N2O is a liquid so it gets to the cylinder as a much denser liquid rather than gaseous O2 thereby not displacing the fuel air mix from the intake manifold. The nitrous changes phase…liquid to a gas…latent heat of vaporization…chills the intake charge (small shots of n2o actually decrease the octane requirement.) It is not reactive until it disassociates to form N2 and O2…see item 1.
3) The extra n2 buffers the combustion process, pure o2 and gasoline vapor tend to detonate.
4) Flame temperature is much lower with n2o.
5) Nitrous bottle presure remains nearly constant…. o2 isn’t liquified so the bottle pressure drops as you remove material.”
There you have it. From the nation’s #1 explosives and combustibles expert! (No kidding.)