Nitro? Whaddaya mean?

And here I thought those things were caused by aging. I guess I learned something new today.

Ed Cregger

But they ARE glow engines, Don.

Ed Cregger

There is nothing about using gasoline fueled engines that would cause us to change from using the term glow to nitro. Or is this the latest generation's version of logic?

Whenever I hear the term nitro being used, I envision monster trucks, the WWF and fat kids bending their parents' credit cards for expensive R/C cars and trucks. None of which has a single thing to do with R/C aircraft.

Yes, the original curmudgeon is back. Hello everyone.

Ed Cregger

Umm, perhaps because you can remove all of the nitro and the engine will still run.

However, your bottle of 30% nitro fuel actually has 50% methanol in the mix.

Now, throw in the fact that these have been glow engines since the mid forties and I think you may get the idea.

Ed Cregger

One of the original uses for nitromethane was as a solvent to clean newspaper printing presses. It was manufactured at the Dupont facility in Deepwater, NJ, USA. I suspect that this was true a very long time before anyone used it as a fuel in automotive engines.

Ed Cregger

Would that be called Guanomite?

Ed Cregger

Because it is powered by methanol based fuel doped with nitromethane. By the same logic I guess we should also call them oil powered, since the fuel generally has about 18% oil in it.

The glow engine began it's life as a methanol/oil system, some smart guy figuring out that platinum based elements catalytically maintain methanol ignition once heated. Then people added nitromethane to it to improve performance. Nitromethane is an additive to a baseline fuel based in methanol. Yes it is used in large percentages in some fuels but the fundamental system is the same.

Last time I looked 30% nitromethane fuel has way more methanol in it than "nitro". And, methanol has more BTU per pound than nitromethane. Go figure that one out..

Mike D.

Not sure, Ed. I guess I'm guano go look it up. ;-)

As I have said before, nitro is an engine designer's crutch.

Ed Cregger

True, Bud :-)

Yeah I know how it works. I was (good naturedly) ribbing the other writer with the BTU question etc. Of course the answer is that the stoichiometric air:fuel ratio for nitromethane is far lower than that for methanol, and since the engine is just a pump the way to increase the mass of the fuel/air charge per stroke is to make as much of it as possible dense liquid versus gas. Assuming of course that one does not care about fuel economy, only horsepower.

So you would also think that synthetics oils, anti-foaming agents, anti-corrosion additives and every other component is also a crutch? The fact that some nitro makes ALL glow engines run better doesn't make it a crutch. It is a fact of life. Very few engines NEED nitro. All will run better with SOME nitro.

So all the top fuel dragsters use nitro as a patch to get the power they need, mabey they should just learn how to build more powerful engines instead.

Hi, Paul.

I knew I could get you to take the bait!

I said nothing about anti-foaming agents or synthetic oil. You are extrapolating again, but that's just you.

Glad to see you are still around and active.

Ed Cregger

Some allegedly don't. Its a pure waste of time. It all depends on the RPM and the breathing and the compression ratio. If your engine is high comp (I think) and already near the point of detonation, then higher cylinder pressures will not extract more power - just ruin the engine.

Its just easier to design a nitro engine.

Yes, they could. However mostly they are adapting stock engines, and nitro and supercharging os a simple way to crank more out up to the point the engines basically explode.

They COULD get more my making them rev higher, but what would be the point? Ther can use the stuff, sio=o its eaiser to do it than actually have to learn something about engine design.

Brute force and ignorance and throwing money rather than intelligence at a problem is as American as Apple Pie...:-)

>

Stock? Hardly. The only thing in common is they have parts that LOOK familiar.

Read the specs at the end. 9500 RPM out of a big block is a feat.

Well, we all can't compete in the Olympics can we? Different strokes. Ignorance? Not as much as that statement. It's one of the things that keep us (and this life) interesting.

Greg

Thought you guys might like this.

• One Top Fuel dragster 500 cubic inch Hemi engine makes more horsepower than the first 4 rows at the Daytona 500.

• Under full throttle, a dragster engine consumes 1-1/2 gallons of nitromethane per second; a fully loaded 747 consumes jet fuel at the same rate with 25% less energy being produced.

• A stock Dodge Hemi V8 engine cannot produce enough power to drive the dragster supercharger.

• With 3000 CFM of air being rammed in by the supercharger on overdrive, the fuel mixture is compressed into a near-solid form before ignition. Cylinders run on the verge of hydraulic lock at full throttle.

• At the stoichiometric (stoichiometry methodology and technology by which quantities of reactants and products in chemical reactions are determined)

1.71 air/fuel mixture for nitromethane the flame front temperature 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.

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

• Spark plug electrodes are totally consumed during a pass. After ½ 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 the fuel flow.

• If spark momentarily fails early in the run, unburned nitro builds up in the affected cylinders and then explodes with sufficient force to blow cylinder heads off the block in pieces or split the block in half.

• In order to exceed 300 mph in 4.5 seconds dragsters must accelerate an average of over 4G's. In order to reach 200 mph well before half-track, the launch acceleration approaches 8G's.

• Dragsters reach over 300 miles per hour before you have completed reading this sentence.

• Top Fuel Engines turn approximately 540 revolutions from light to light!

• Including the burnout the engine must only survive 900 revolutions under load.

• The redline is actually quite high at 9500rpm.

• The Bottom Line; Assuming all the equipment is paid off, the crew worked for free, and for once NOTHING BLOWS UP, each run costs an estimated ,000.00 per second. The current Top Fuel dragster elapsed time record is

4.441 seconds for the quarter mile (10/05/03, Tony Schumacher). The top speed record is 333.00 mph. (533 km/h) as measured over the last 66' of the run (09/28/03 Doug Kalitta).

Putting all of this into perspective You are driving the average $140,000 Lingenfelter "twin-turbo" powered Corvette Z06. Over a mile up the road, a Top Fuel dragster is staged and ready to launch down a quarter mile strip as you pass. You have the advantage of a flying start. You run the 'Vette hard up through the gears and blast across the starting line and past the dragster at an honest 200 mph.

The 'tree' goes green for both of you at that moment. The dragster launches and starts after you. You keep your foot down hard, but you hear an incredibly brutal whine that sears your eardrums and within 3 seconds the dragster catches and passes you. He beats you to the finish line, a quarter mile away from where you just passed him.

Think about it, from a standing start, the dragster had spotted you 200 mph and not only caught, but nearly blasted you off the road when he passed you within a mere 1320 foot long race course.

That folks, is acceleration.

If the engine is that high in compression, then the addition of a head gasket will tame the beast. FAI pylon motors run straight fuel and are a terrible bitch to adjust and still don't put out the power that a good F1 engine does.

Shows how little you know about drag racing engines. NONE of the top fuel engines are stock motors. They are purpose built engines, usually Donovans, that put out huge amounts of torque and HP. Making them rev higher is not an optiion as they are limited by piston speeds and the ability to pump oil to the moving parts.

If thte Brits are so good at engine design, why haven't THEY built an all-conquering drag engine?