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sounds like a fun time jerry. my dad run a B alter i think they may have got some nitro from ron elis. i was just a kid but they called it helicopter juice ??or windmill juice?? all i know was the hemi lifted the head and dump water under the slicks and the fire truck was running down the track at tri city they came back with a hurt hemi and dad had to put new studs in the deck i still remember trying to help when my dad then he was trying to put the iron main cap girdle on under the T after the hemi lifting the head dad said it never ran the same and said he wish he never used the stuff what ever they put in the tank
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Pat
we had good luck with it----but we ran lower static compression and less timing
Most people got in trouble with it because you need lots more fuel to get the mixture right and less timing . Also most gas or alky motors were higher compression and couldn't stand the extra cylinder pressure
We did have a fuel pump go weak on us once and we threw away every thing outta the short block but the studs , nuts and washers
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yup i am sure dad was not up to speed on what ever they used the learning cure was $$ more then he could take .i still wish i had all the hemi s and the T
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we used to watch both sides of the road as we drove, watching for them 300s setting out behind a barn---when Donovan got his block out it sure was easier
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yes we some of them old tanks that dad towed home . i remember kicking holes thru the rusty rockers of the bodys . dad had hemi cranks in the house by the back door dad did think it was a good spot till one fell on moms foot:eek:
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Tech1, Thanks for the kind words. There are easy answers and complicated answers. First the easy answers at
http://www.nitromethane.com/
There we see the "autoignition temperature" of 315 degrees C similar to the 320 value you mentioned. Of more interest is the autoignition pressure of 62.3 atm. That high pressure seems out of reach but simple Diesel engine considerations show that compression ratios as low as 12:1 can approach such pressures and also easily exceed the autoignition temperature so it would be disastrous to use nitromethane in a diesel engine with a typical compression ratio of 22:1, that would give new meaning to the term "engine knock"! That explains why comments above refer to high concentrations of nitromethane used in low compression engines. A little surprise to me is the fact that the boiling point of nitromethane is about 103 degrees C and higher than I recalled, but there are numerous warnings to DO NOT DISTILL NITROMETHANE! Another site gives the Racer's viewpoint at
http://ch3no2.com/
Now for some complicated answers I note that a certain Prof. Smook at Cornell University has made extensive studies of just burning methane with oxygen and found it takes over 100 individual processes to describe all the reactions in such a "simple" flame. Other research by the Air Force (AFOSR) is well established in using models of many hundreds of reactions going on in a jet engine to explain such "combustion". The point is that in a "flame" there are many transient chemical species that don't last very long but are still there in the overall reaction so it looks like methane would burn simply as
CH4 + 2O2 -> CO2 + 2H2O + heat
but actually there is a whole lot of hot stuff going on! One further point is that research on energetic materials is where calculations can be very useful to investigate the energy of reactions using computer calculations without doing dangerous laboratory tests. Overall the key idea is that almost all such materials involve unstable organic nitro compounds. In research there are lists of many nitro compounds of varying explosive violence but of course you have to stabilize them somehow for sensible use and that is where the money comes from for the Nobel Prizes, the invention of stabilized TNT by Alfred Nobel. I want to stick to just racing fuels here since the topic of explosives on an open Internet site is not a good idea these days. To cover my rear I warn that nitromethane can be ignited by shock or heat over 315 degrees C but if a racer is careful and the driveline is prepped for the abuse, limited amounts of nitromethane "fuel" can give tremendous power boosts.
Don Shillady
Retired Scientist/teen rodder
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How we limited the amount was the biggest pump we could get and a fuel tank that had some left at the end of the quarter
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Maybe I glossed over a detail. While you can write a simple equation for a combustion reaction, in the actual event there is a lot of "hells-a-poppin" collisions between hot molecules that break bonds to give broken pieces with an odd number of electrons while nature prefers compounds with an even number of electrons. They break more until some even combination of electrons is reached in the final results at a lower energy. While an engine running at 5000 rpm only fires 2500 times per minute that is a relatively long time of about (2500/60) times per second or about 0.024 seconds per explosion. Compare this to molecular collisions of about 10**30 collisions per second in one cubic cm (about 0.061 cu in). That is about (1 million)x(1 million)x(1 million)x(1 million)x(1 million) collisions per second in one cubic cm. This means that to study combustion reactions the formation and destruction of many intermediate fragments of molecules have to be accounted for and so once nitromethane gets started fragmenting, that O2 part can come off and be available for reaction to form CO2. Even at high rpm the mechanical parts of an engine are moving much slower than the chemical reactions.
Don Shillady
Retired Scientist/teen rodder
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Don,,, in order to keep all this 'fathomeable). Hot rodders past and present, for the most part, are able to grasp the anatomy of combustion on the molecular theory,,,, 1 atom fuel ($) 1 atom air (no typo) $ 1 match and we have ignition. Fortunately and unbeknownst,,, we have a cumbustion chamber floor (the piston) that readily heads south to escape the hostile environment and thusly converts our thermal energy into rotating energy. Feeding the monster huge amounts of volatile fuel, may sometimes not be digestable,,, In my blown pickle fork boat, I was always mindful of disaster and used aluminum bolts to secure my huffer,,,, better my Littlefield go on a leash, than my crank going out the bottom,,,, ps. I like your input :)
