It sounds like advertising trash. those guys never let the truth get in the way of a good story. The only one I would agree with is heads have been known to blow the bolts but that is because the are designed to to save blocks and cranks . Yes I agree the blower will normally blow off first and they have safety straps to keep them with the car when they do.
Steve ----- Original Message ----- From: <[EMAIL PROTECTED]> To: "Multiple recipients of list" <[EMAIL PROTECTED]> Sent: Wednesday, December 17, 2003 3:11 AM Subject: More critical thinking please > >* One Top Fuel dragster 500 cubic inch Hemi engine makes more horsepower > >than the first 4 rows at the Daytona 500. > > The usual figures given for digger output are between 7000 and 8000 Hp, and > the latter sounds high to me. The figures for NASCAR run up to 780 Hp. I > asked around web and got figures of 8 and 12 cars in front four rows and I > don't know myself. If 8 cars, total Hp is 6240, and hence above is true. If > 12, total Hp is 9360 and above is not true. Anyone can juggle figures to > get results he likes, so no hard and fast truth is available. > > >* A stock Dodge 426 Hemi V8 engine cannot produce enough power to drive the > >dragster's supercharger. > > A quick intuitive feeling for this can be had in looking at the timing belt > that drives the blower. It may be three inches wide ... anyone think it > could safely transmit 350 Hp at the pully radius of a digger crank? IOW, > most probably yer 426 could easily run the blower. > > >* 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 9500 RPM the above 500 CID motor passes only 1375 CFM. That means given > the 3000CFM above the blower supplies boost of roughly 2.2 atmospheres. > Given 10:1 CR, that means 470 PSI in cyls at room temp. Since the mix is > also heated, I would give the max compression about 525-550 PSI. That is > hardly enough make the mix turn solid. Some Diesels in fact have almost > that much max pressure; my VW Rabbit had 450 PSI spec'd. It is impossible > to even liquify air by pressure alone and I don't think it can be made > solid at temps much over AZ. > > >* Nitromethane burns yellow. > > Nitro and alky, both used in model airplane fuel, both burn blue. > > >The spectacular white flame seen above the > >stacks at night is raw burning hydrogen, dissociated from atmospheric water > >vapor by the searing exhaust gases. > > Water vapor constitutes way too small a fraction of air to do that, and it > doesn't disassociate at those temps anyhow. Water is generated by > combustion, but it's just that: water. > > >* Dual magnetos supply 44 amps to each spark plug. This is the output of an > >arc welder in each cylinder. > > If you assume 30,000 average volts at the plug, that would be an > instantaneous 1,320,000 watts each. Typical spark duration is about .025 > sec and a Joule is one watt-sec, so the energy in that spark is 33,000 > Joules. The digger motor makes let's say 1000 Hp per cyl per spark. One Hp > is 746 watts, so the motor makes 746,000 watts per power stroke. If the > power stroke is 120 deg long, it takes about .019 sec at 9500 RPM. Hence > the energy is 14175 joules. IOW, at the figures given above, it takes 2.3 > times as much energy to make the spark as the motor produces. That is > singularly absurd!! > > Most maggies and indeed most iggies have primary currents of about 3 amps > and primary voltages of 350-400. The actual wattage then is at best about > 1200 watts. The efficiency is probably 85-90%, so actual output in the > spark is in range of 1000 Watts or 25 Joules. Even if your primary current > in racing maggies is twice as high, the energy is still only 50 Joules. > > >* 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. > > No doubt plugs do erode but I doubt they go completely away each pass. > These engines are shut down by cutting off fuel, indeed, to prevent > Dieseling. I wouldn't concede that the ignition is by hot valve heads > though, it's still spark-controlled. > > >* 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 usual result is a blower explosion; blower has a lot more internal > volume and is nowhere near as stoutly constructed as the motor asm itself. > Never heard of heads coming off. > > >* Including the burnout the engine must only survive 900 revolutions under > >load. > > Real close. > > Now as for that 200 MPH motorcycle getting beat by the digger ... it's > true. It takes 4.5 sec for a 1/4 mile at 200 MPH. The digger record is 4.41 > sec. The dragster crosses the finish line while the biker is still 26 feet > away. That's acceleration fersure. > > I wondered where the material in original post came from ... am always > suspicious of un-ref'd text. This is the cross I bear from having been > scientifically trained. For other interesting facts, and those a bit more > reasonable, see: http://www.nhra.com/streetlegal/funfacts.html
