History of nitromethane in drag racing

[flapjack]

Found this today:

http://www.hotrod.com/how-to/engine/hrdp-1304-what-is-nitromethane-anyway/

 

[Dennis]

That was a really good read!

 

[robslob]

I understand that both the nazis and the U.S. experimented with Nitro as an avaition fuel for high altitude flight. One has to wonder what an Allison would sound like on pop.....Jim Lytle?

 

[DrRocket]

Great read. Thanks for the link, Tom.

Allison heck, they sound tame next to a Rolls Royce/Packard Merlin. I'd like to hear one of those on pop!

 

[Gordon]

Very interesting and enjoyable read, thanks for posting. I did find it funny that it mentions not recommending running 100%, but the Surfers ran 100%, or very, very close to it and did pretty well.

http://www.hotrod.com/features/history/stories/hrdp-9810-southern-california-top-fuel-movement/

 

[Muddy]

I well remember several times we packed it in ice to get the percentage up beyond 100%. Remember the hydrometer assumes the nitro is at 70 (?) degrees. We could pack it in ice and get an few extra percentage points sometimes well above 100%.

 

[Nitrohelper]

..........hydrometer assumes the nitro is at 70 (?) degrees....

The Hydrometer does not measure Nitro percentage - it measures the specific gravity of the liquid...
The hydrometer is calibrated by temperature and the percentage is a calculated number based on the specific gravity...

By chilling the Nitro the specific gravity is changed Not the percentage ,100% is 100% at any temperature...

To know the accurate Nitro percentage to one decimal point I use a digital meter from Anton-Paar ,
of course it costs $3500 instead of $100 for a hydrometer...

 

[flapjack]

To know the accurate Nitro percentage to one decimal point I use a digital meter from Anton-Paar ,
of course it costs $3500 instead of $100 for a hydrometer...

Looks like they've come down in price since I last looked. I was looking to get a digital meter for getting specific gravity of home brew, but then my get up and go for the project went by the wayside. And I wasn't going to spend that much. Besides, I know how to use a hydrometer, my dad showed me when he worked for the pipeline company and testing the specific gravity of the refined product coming down the pipes.

 

[Muddy]

The Hydrometer does not measure Nitro percentage - it measures the specific gravity of the liquid...
The hydrometer is calibrated by temperature and the percentage is a calculated number based on the specific gravity...

By chilling the Nitro the specific gravity is changed Not the percentage ,100% is 100% at any temperature...

To know the accurate Nitro percentage to one decimal point I use a digital meter from Anton-Paar ,
of course it costs $3500 instead of $100 for a hydrometer...

You are of course correct. I simply chose to take the less technical path. The warmer the nitro the lower the reading on the hydrometer. Hence by packing it in ice we were assured a higher percentage reading. I seem to remember the scale went to 110 or something near that. By packing it in ice we could achieve readings of 102-104 depending on weather conditions that day. By doing this it was a bit hard on parts but if it was the last chance to qualify at Indy you just had to set lower in the seat, tighten the seat belts and let it all hang out.

 

[Nitrohelper]

.......doing this it was a bit hard on parts ..........

It wouldn't be any harder on parts because you were not changing the percentage of Nitro,
you were only changing the hydrometer calibration point...

 

[flapjack]

It wouldn't be any harder on parts because you were not changing the percentage of Nitro,
you were only changing the hydrometer calibration point...

But isn't it the case that when you chill the fuel, it gets more dense, so a given volume of fuel will have more bang for the buck, even if the percentage of nitro in the mixture is the same?

 

[Muddy]

.Bingo, thank you Tom. As the density increases the reading on the hydrometer increases. Jerry is technically correct about the percentage in a chemical analysis. It's either 100% percent or its diluted with something,.but because the hydrometer is calibrated assuming a base temperature, the readings will vary based on the temperature of the nitro. You can take a beaker of nitro that been sitting out in 100 degree sun and put it in ice for a while and the reading will change several points which we commonly (perhaps in error) call percentage points. Jerry you and I are debating apples and oranges. And by the way when the reading on the hydrometer goes up so does the possibility of broken parts.