Fuel Mixture nitromethane

[cavalierchristian]

has nayone tried running nitromethane in these engines? like maybe a 50/50 mix with gas(and oil of course). I know the engine would run hot. REALLY hot, but would the crank, connecting rod and my worry crank bearing withold the extra power? my guess is it would easily gain another 4-5 hp... but again, will run extremely hot... anyone with experience or just wanna throw in ther 2 cents is much appreciated

 

[crassius]

Most of these engines will go 30 to 35 mph. That's REAL fast for a frame & brakes that were never designed for that speed. Also, the main bearings tend to fail pretty quickly with a lot of riding at anything above about 20 to 25 mph. Not a problem for folks that can afford to throw another of these cheap engines in every 6 months or so, but hard on the poor guy barely managing to get back & forth to a minimum-wage job every day.

I used to run alcohol in the 70s, jetting needs to up by about 150% for it, but it should work OK.

 

[Fabian]

Nitromethane doesn't like to mix with gasoline and separates out of solution into two layers.

If you really want to increase power (naturally for off-street use on a closed circuit course) the additive will need to be nitroethane as it readily mixes with gasoline.
This will require jetting changes which prevent use of ordinary gasoline unless the jetting is altered to suit the new fuel - sounds a pain in the backside to me.

At the end of the day, an oxygenated additive is pointless as the standard engine provides enough power for sensible street riding of 20 miles an hour.
All improvements should be focused at boosting torque in the low and midrange rpm.

 

[cavalierchristian]

thanks for the responses. and thanks for the reference to nitroethane. Im not worried about blowing through engines, nor jetting concernes (can have a carb for gas/carb for alt. fuel). I wonder what can be done to help the main bearing, and how quickly it would take the engine to overheat. I also wonder if the head while LITERALLY explode off the first time i run the nitro meth/ethane. I have about a gallon of nitromethane laying around from back when I had a t-maxx... and the stuff isnt cheap, so I am debating to run the fuel or not. Im have taken a big pay cut in my current employment, so buying a new engine would suck, but wouldnt put me under.

 

[Fabian]

It's not so much "you" being not worried about blowing up engines, but the effect it can have on other people who desperately rely on their motorized bicycle for transport.
Those persons are trying to quietly and stealthily fly under the radar and not attract attention to themselves, whilst being mindful not to make a train wreck of the hobby by having the police implement draconian crack downs on motor bicyclists.

Riding around on the streets or bicycle paths with a noisy and fast motorized bicycle is a sure way to f*ck it up for those who are doing their best to be invisible to the law.

 

[motorpsycho]

nitro?
are you talking REAL nitro as in used in top fuel funny cars?
or are you talking about the nirto used for r/c cars?
If your talking real nitro, i don't think the ignition system on one of these engines has enough spark to even ignite it.
real nitro turns into almost a solid once it's in the combustion chamber and you need at least 44 amps in the cylinder to fire it.

some interesting facts about a nitro top fuel engine:
One dragster's 500-inch Hemi makes more horsepower then the first 8 rows at Daytona.

* Under full throttle, a dragster engine consumes 1 1/2 gallons of nitro per second, the same rate of fuel consumption as a fully loaded 747 but with 4 times the energy volume.

* The supercharger takes more power to drive than a stock hemi makes.

* Even with nearly 3000 CFM of air being rammed in by the supercharger on overdrive, the fuel mixture is compressed into nearly-solid form before ignition. Cylinders run on the verge of hydraulic lock.

* Dual magnetos apply 44 amps to each spark plug. This is the output of an arc welder in each cylinder.

* At stoichiometric (exact) 1.7:1 air/fuel mixture (for nitro), the flame front of nitromethane measures 7050 degrees F.

* Nitromethane burns yellow. The spectacular white flame seen above the stacks at night is raw burning hydrogen, dissociated from atmospheric water vapor by the searing exhaust gases.

* Spark plug electrodes are totally consumed during a pass. After 1/2 way, the engine is dieseling from compression-plus the glow of exhaust valves at 1400 degrees F. The engine can only be shut down by cutting off its fuel flow.

* If spark momentarily fails early in the run, unburned nitro builds up in those cylinders and then explodes with a force that can blow cylinder heads off the block in pieces or blow the block in half.

* Dragsters twist the crank (torsionally) so far (20 degrees in the big end of the track) that sometimes cam lobes are ground offset from front to rear to re-phase the valve timing somewhere closer to synchronization with the pistons.

* To exceed 300mph in 4.5 seconds dragsters must accelerate at an average of over 4G's. But in reaching 200 mph well before 1/2 track, launch acceleration is closer to 8G's.

* If all the equipment is paid off, the crew worked for free, and for once NOTHING BLOWS UP, each run costs $1000.00 per second.

* Dragsters reach over 300 miles per hour before you have read this sentence.

Did you know …

… that the nitromethane-powered engines of NHRA Top Fuel dragsters and Funny Cars produce approximately 7,000 horsepower, about 37 times that of the average street car?

… that one cylinder of the eight cylinders of a Top Fuel dragster or a Funny Car produces 750 horsepower, equaling the entire horsepower output of a NASCAR engine?

… that the gasoline-powered engines of NHRA Pro Stock cars produce about 1,200 horsepower, about eight times that of the average street car?

… that an NHRA Top Fuel dragster accelerates from 0 to 100 mph in less than .8-second, almost 11 seconds quicker than it takes a production Porsche 911 Turbo to reach the same speed?

… that an NHRA Top Fuel dragster leaves the starting line with a force nearly five times that of gravity, the same force of the space shuttle when it leaves the launching pad at Cape Canaveral?

… that an NHRA Funny Car is slowed by a reverse force more than seven times that of gravity when both parachutes deploy simultaneously?

… that NHRA Top Fuel dragsters and Funny Cars consume between four and five gallons of fuel during a quarter-mile run, which is equivalent to between 16 and 20 gallons per mile?

… that NHRA Top Fuel dragsters and Funny Cars use between 10 and 12 gallons of fuel for a complete pass, including the burnout, backup to the starting line, and quarter-mile run?

… that NHRA Top Fuel dragsters and Funny Cars travel the length of more than four football fields in less than five seconds?

… that NHRA Top Fuel dragsters can exceed 280 mph in just 660 feet?

… that from a standing start, NHRA Top Fuel dragsters accelerate faster than a jumbo jet, a fighter jet, and a Formula One race car?

… that a fuel pump for an NHRA Top Fuel dragster and Funny Car delivers 65 gallons of fuel per minute, equivalent to eight bathroom showers running at the same time?

… that the fuel-line pressure for NHRA Top Fuel dragsters and Funny Cars is between 400 and 500 pounds, about 20 times greater than the pressure on passenger-car fuel pumps?

… that depending on size and angle, the large rear wing on an NHRA Top Fuel dragster develops between 4,000 and 8,000 pounds of downforce?

… that the 17-inch rear tires used on NHRA Top Fuel dragsters and Funny Cars wear out after four to six runs, or about two miles? Some brands of passenger-car tires are guaranteed for 80,000 miles.

… that it takes just 15/100ths of a second for all 7,000 horsepower of an NHRA Top Fuel dragster engine to reach the rear wheels?

… that it's desirable for an NHRA Top Fuel dragster to race with its front wheels inches off the ground for about the first 200 feet of the run? This ensures proper weight transfer to the rear wheels, a crucial part of a good launch and quick run.

… that the nitromethane used to power the engines of NHRA Top Fuel dragsters and Funny Cars costs about $30 per gallon?