Two Stroke Motocross
Two Stroke Motocross Forum => Open Forum => Topic started by: TMKIWI on July 08, 2011, 03:12:24 PM
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> First, some useful info:
>
> One Top Fuel dragster 500 cubic inch Hemi engine makes more horsepower
> than
> the first 4 rows at the Indy. 500.
>
> Under full throttle, a Top Fuel dragster engine consumes 1.5 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 426 Hemi V8 engine cannot produce enough power to drive the
> dragster's 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 1.7:1 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 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 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.
>
> The crankshaft twists so much that the camshaft lobes are ground offset
> from
> the front to the rear to re-phase the vave timing to achieve
> synchronisation
> with the pistons.
>
> In order to exceed 300 mph in 4.5 seconds dragsters must accelerate at 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 red-line is actually quite high at 9500 rpm.
>
> 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
> US$1,000.00 per second or around US$4,500.00 per pass.
>
> The current Top Fuel dragster elapsed time record is 4.441 seconds for the
> quarter mile (10/05/03,Tony Scumacher). 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 riding the average $250,000 Honda MotoGP bike.
> 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 RC211V hard up through the gears and blast across the
> starting line and past the dragster at an honest 200 mph (293 ft/sec).
> The 'tree' goes green for both of you at that moment. The dragster
> launches
> and starts after you.
> You keep your wrist cranked 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.
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I bet if you repainted that Honda blue it would go faster. ::)
P.S. This thing would have some acceleration...
Tul-Aris 2-stroke racer (http://www.youtube.com/watch?v=jQoY7ECyoN8#)
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Drag racing is another sport I love. The sound of those Nitro motors when they launch. I cant even consider it sound -- it's a concussion that tears through your chest.
Was at big race weekend ages ago, and was cruising the pits. Saw a motor torn down with the last runs blown motor parts on a table for display. The motor had lost a head gasket during its pass, and the hot combustion gases burned a hole through the aluminum head along the mating surface -- as if someone hit it with oxy/acetylene. I'm not sure if the block survived.
The head was HUGE. I can't imagine how expensive one of those things are... let alone to consider all of those parts to be consumable. I can't figure how how anyone can afford to run them.
What's the saying? Gasoline is for cleaning parts, alcohol for drinkin, and nitro is for racing?
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Long time ago I went to the Snowbird Nationals at Desoto Raceway near Sarasota FL. One car did blow the head off near the starting line. I remember seeing the glowing orange cylinder holes in the nightlight as though it was yesterday. Thanks for all those facts that I always appreciated but never knew.