About Fuel

[RidgeRunner]

Re: #7

Russ,

     Greek reportedly used Hydrazine on his 200+ run at Alton Ill.   Gave up trying to use it back then on a regular basis because he found it too unstable/unpredictable with breakage/race losses exceeding appearance/prize money of the day.

     Comments/corrections/more details from more serious history buffs or those in the know more than I are welcomed.

                            Ed Purinton

[RidgeRunner]

Re: #13

Jack,

     ..........remember the Posi-Fuel?  Yes, still have it buried in my pile of necessary classical objects in the cellar.       
Very similar to the Lake.  One a knock off of the other?  Some thinking of the day thought they gained volume at too much expense of velocity but I liked the simplicity of tunning it.   Ran it on M/C #57A in '72, holed the piston, always thought cause was more timing issue than fuel.  Ran good on the street later, just had to remember to shut off the fuel petcock when parking the bike...........    Slightly unique starting drill, never worried about average thief starting it up and riding off. 

                                      Ed Purinton

[Dean Los Angeles]

If you run the fuel class I was under the impression that what you put in the tank was your own business..russ

Depends on if your racing is rule based or cheatin based!
Rule 2.B spells out the approved fuels that are listed at the top of this topic. On the other hand, filling the frame tubing with nitrous oxide for the gas class, relying on the fact that for fuel class tanks aren't checked . . .

I worked with a buddy that ran a stock-appearing kart class that didn't allow carburetor modifications and had fixed jets. There were no restrictions on fuel. Normally you ran 15-20% fuel depending on weather.

An RC engine carburetor fit in the magneto case with fuel supplied through the coil wire insulation. (T-fitting under the seat.) He won two national championships by never using the full power available, just enough to squeeze past the guy ahead of him. Perfectly legal.

Not enough fuel through the float needle? I'm up against that right now. Fixed it with two carburetors.

I could go on for pages. Dolan could go on for days.

[JackD]

"Cheating is in the eye of the beholder." (Me)
"The best officials know the most about cheating and should stay at least 1 step ahead but you have to be fair." (Me again)
Cheaters and bad officials really hate that. 

[desotoman]

One problem with nitro in small motors is you main jet gets larger than you float needle and seat.

True, and the exact reason there was a 4x2 intake manifold made for the Flathead ford V8. In the old days if you were running a Flathead ford V8 on gas and using a 3x2 intake manifold you would never show any vacuum on a gage in the intake manifold. But if you were running nitro you needed the extra carb that the 4x2 gave you to give the motor the extra fuel it needed.

Tom G.

[dwarner]

Dean,

I'm surprised - reread rule 2.B Fuels. The listed fuels are "examples" only. If we were to list all approved fuel combinations it would lead to sleepiness as Jack mentioned in another post about repetitive responses.

In the fuel classes ANYTHING is legal other than the event gasoline.

DW

[Dean Los Angeles]

I'm surprised - reread rule 2.B Fuels. The listed fuels are "examples" only. If we were to list all approved fuel combinations it would lead to sleepiness as Jack mentioned in another post about repetitive responses.

In the fuel classes ANYTHING is legal other than the event gasoline.

"2.B Fuels: In fuel classes, any approved liquid fuel may be used, Examples of approved . . ."

Interesting. If you can run anything why would the word "approved" be used. Bring on the hydrazine, acetylene, propylene oxide, ethyl acrylate, ethylene oxide, benzidine, ammonium perchlorate . . .

[dwarner]

Because fuel "approved" for the fuel classes is other than event gas.

DW

[JackD]

Gun powder shows promise.
You should be able to run it in the sparky and non sparkling classes.
 I will buy it if you want to try it.

[russ jensen]

The flame speed shows the real difference. Nitrous oxide is in the upper range of air, oxygen is several magnitudes higher and instead of a flame front you get an explosion, and the engine won’t take that kind of stress.
                                         Temperature   Flame Speed
Fuel              Oxidant          ( C )              ( m/s )
Acetylene       Air                2400              1.60 - 2.70
                    Nitrous Oxide  2800              2.60
                    Oxygen          3140              8.00 - 24.80


Is this a valid comparison to gas?? or from memory doesn't acetylene have a c-c triple bond which makes it sort of like nitroglycerin  above 15 psi.? If this is a valid com ; I would think that this flame speed could be used  to cure problem Jack referred to in earlier post about fuel not burning fast enough for high piston speed eng. O2 could be blended to nitrous{would think the 2 would stay mixed} or in place of nitrous- blend nitrogen and  O2 @ rate higher than air  so when eng reaches point that the burn wont spin it faster -hit the button & away we go??? Just something thats been wearing my brain smooth while rebuilding  John Deere clutches today{very boring job} .russ

[ddahlgren]

OK show of hands how many actually have run 300 hp of nitrous or nitro more than 20% in this thread..sigh... and not on a kart or rc plane..Glad to hear nitrogen became important in the combustion process inside of the cylinder as well.. Nitrous does not hit hard if done right..nitro at high rpm is a waste of time as well...
Dave

[maguromic]

Dave is right.  Your tune up is far more important, also remember if its is humid, that water droplets will pass through the system. I believe on a Chevy big block at 8000 rpm with 50% humidity its about one quart a second.  I might have to double check the charts but I think I am close.  If you look at some of the pro teams in racing they have charts for this scenario and adjust the tune up accordingly.  Especially at high altitude.

[russ jensen]

OK show of hands how many actually have run  nitro more than 20% in this thread.

Don't know how to show a raise hand,but mine is up..russ

[jimmy six]

70+%. The more we used the, less RPM we turned, the bigger the gear, the taller the tire, the faster we went.

Good Luck

[russ jensen]

Gun powder shows promise.
You should be able to run it in the sparky and non sparkling classes.
 I will buy it if you want to try it.

Just emptied 100 lb drum  of 5010- {can't believe we shot up the whole drum} but how does one get the stuff into eng??  besides most smokeless powder burns to slow for any rpm potential & black powder will only develop 70000 lb pressure when packed solid- are you sure powder really shows promise??? If I can't make it work in eng can I keep unused portion to use in rifles??russ