nitrous

Just curious. Why is nitrous used instead of liquid oxygen. Is it becous lox is more difficult to store (lower temperature) ?

G
Reply to
Gene Wagenbreth
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My theory...

For oxygen to be in a liquid state, it has to be less than -182.95 ºC, or close to -300ºF. When this liquid would hit the engine, which is running at approximately 200ºF, there is giong to be a serious problem with heat transfer, rapid cooling and cracking of any metal part that it comes in contact with that's under stress (read: pistons, cylinder heads, block), etc at the very least.

While part of N20's benefit is its cooling effect, an extreme amount of cooling such as a 500 degree difference injected under pressure will probably amount to something more reminiscent of an explosion than a performance boost.

JS

Reply to
JS

Pure O2 injection has been done. The issue is not storage or handling but tuning and combustion control. Pure oxygen injection requires significant fuel increase to prevent lean conditions and to buffer the combustion process, otherwise exhaust gas temperatures rise very quickly and combustion occurs too rapidly. It turns out that the power production increase is marginal compared to N2O, because of the richness necessary, but the headaches due to maintaining the tune are significantly greater. If the tune on an O2 injection systems slips the combustion rate jumps really quickly and the best case is the motor burns down hard, the worst case is the motor explodes.

It takes a relatively bigger slip in the tune to make an N20 system come down hard. N2O liberates it's O in a much more controlled fashion, absorbing some heat in the process. The N in the mixture also absorbs some heat, thus buffering the combustion process and making tuning a little more consistent. And the exhaust gas temperatures are much lower for a much less rich mixture.

Some folks have also combined a pure O2 stream with other chemicals in order to provide the required buffering. For example, water and alcohol have been used. But the results are no better than N2O and now you've got to handle twice the fluid injection components.

Reply to
Dan

Well said, Dan...... I can only add that it is the combustion process that liberates the O2 from the N2O. This adds predictability to the equation.

Pure O2 around petrochemicals just kinda makes my skin crawl....... Things that wouldn't normally even consider burning can get real funny in the presence of pure O2.

Reply to
Jim Warman

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