blimey... Top Fuel Drag Engines...

[GTRSTILL]

Fuel is injected by a constant flow injection system. There is an engine driven mechanical fuel pump and about 42 fuel nozzles. The pump can flow 100 gallons per minute at 8000 rpm and 500 PSI fuel pressure. In general 10 injectors are placed in the injector hat above the supercharger, 16 in the intake manifold and two per cylinder in the cylinder head. Usually a race is started with a leaner mixture, then as the clutch begins to tighten as the engine speed builds, the air/fuel mixture is enriched. As engine speed builds pump pressure the mixture is made leaner to maintain a predetermined ratio that is based on many factors, one of which is primary one of race track surface friction. The stoichiometry of both methanol and nitromethane is considerably greater than that of racing gasoline, as they have oxygen atoms attached to their carbon chains and gasoline does not. This means that a "fueler" engine will provide power over a very broad range from very lean to very rich mixtures. Thus, to attain maximum performance, before each race, by varying the level of fuel supplied to the engine, the mechanical crew may select power outputs barely below the limits of tire traction. Power outputs which create tire slippage will "smoke the tires" and the race is often lost.

The air/fuel mixture is ignited by two 14 mm spark plugs per cylinder. These plugs are fired by two 44-ampere magnetos. Normal ignition timing is 58-65 degrees BTDC. (This is dramatically greater spark advance than in a gasoline engine as "nitro" and alcohol burn far slower.) Directly after launch the timing is typically decreased by about 25 degrees for a short time as this gives the tires time to reach their correct shape. The ignition system limits the engine speed to 8400 rpm. The ignition system provides initial 50,000 volts and 1.2 amperes. The long duration spark (up to 26 degrees) provides energy of 950 millijoules. The plugs are placed in such a way that they are cooled by the incoming charge. The ignition system is not allowed to respond to real time information (no computer-based spark lead adjustments), so instead a timer-based retard system is used.

Billet steel crankshafts are used; they all have a cross plane a.k.a. 90 degree configuration and run in five conventional bearing shells. 180 degree crankshafts have been tried and they can offer increased power, even though the exhaust is of open type. A 180 degree crankshaft is also about 10 kg lighter than 90 degree crankshaft, but they create a lot of vibration. Such is the strength of a top fuel crankshaft that in one incident, the entire engine block was split open and blown off the car during an engine failure, and the crank, with all eight connecting rods and pistons, was left still bolted to the clutch!!!!!!!!!

[ru']

fcuk!

[Rain]

ah, nice and simple

[StretchGSK]

And to some it looks like it a just a big engine with a supercharger.
Love these types of facts!

[xaero1]

They all use the Hemi V8 engine and apparently the supercharger is so big that a Hemi V8 running on gasolene isn't powerful enough to run it!

0-300mph in just over 4 seconds.... incredible stuff!

[Wanabee Kiwi]

Originally Posted by GTRSTILL

Such is the strength of a top fuel crankshaft that in one incident, the entire engine block was split open and blown off the car during an engine failure, and the crank, with all eight connecting rods and pistons, was left still bolted to the clutch!!!!!!!!!

That's awsome, i'd love to see that!

[frostmotorsport]

i have seen a supercharger explosion, where it remained attached to one head, and ripped the other one apart, so the blower flopped over to one side with bits of the head & manifold still attached...

would need a bit more than rings n bearings I feel! very spectacular tho!

nice facts too!

[MacGTR]

I remember reading something on a website that one of these did a 3.7 seconds 1/4mile at 350 odd mp/h at Santa Pod

[kismetcapitan]

the spark plugs are actually *consumed* during a run and by the time the car is on its way, the engine is dieseling!

Also, a top fueler will drink $3000 worth of fuel per pass.

[Richf]

Originally Posted by MacGTR

I remember reading something on a website that one of these did a 3.7 seconds 1/4mile at 350 odd mp/h at Santa Pod

no not that quick 4.7 seconds i think


A short list of Top Fuel dragster facts:

* The 500-inch Hemi makes more horsepower than the first 8 rows at Daytona.

* Under full throttle, a the 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 then 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 electronic 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.

* Nitro methane burns yellow. The spectacular white flame seen
above the exhaust pipes 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 of 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.

* The engines 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 250 mph well before 1/2 track, launch acceleration is closer to 8G's.

* Drivers must shut off before the finish line, or even dual
parachutes will not stop the car.

* 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.

Bear in mind here that the engine behind all this Herculean output is a
modified offshoot of a common American big-block V-8

[Richf]

UK records are 4.70 run by Andy Carter and 312mph by Urs Erbacher

although Andy Carter ran a 4.65 to back up his 4.7 and Urs ran a 318mph run to back up the 312


The legendary 3.6@368mph run was by a hydrogen peroxide rocket car driven by Sammy Miller at Santa pod in 1986 although this times have been disputed by many

YouTube - Vanishing Point 0-400mph in 4 seconds!!!

[jamesbilluk]

that rocket car is insane, found another video of it doing a demo YouTube - Bob Feeler in the ex Vanishing Point rocket car apparently has one of the engines from the applo space craft, and the equivalent of 40,000hp

another one http://uk.youtube.com/watch?v=6CX6Lc...eature=related

[Richf]

The car never did very much when Bob Feeler had it i belive he had trouble getting the fuel

Think rocket cars are mad what about rocket bikes???

YouTube - Eric Teboul 5.7 @198

[Superted]

If these things run on Hydrogen Peroxide, then in essence they are high speed car bombs right?????

Me thinks that this could give al-Qaeda a whole new direction in operations


Actually should this thread be locked?? we could be supporting terrorism, ahahahahaha.


PS - You must have to have your shoulders bolted to you torso, if you go on that rocket bike, they'd be popping out all the time on that thing

[kismetcapitan]

it's too bad engine development has been locked with the NHRA - if '60s Hemi engines are making this kind of power, I wonder what could have been developed with no restrictions on engine design.

btw I did some rough estimates on running nitromethane as a fuel for GT-Rs. We'd need 8000cc injectors (or some equivalent), 16 Bosch 044 pumps, and although fuel costs would merely quintuple, I don't know what the mpg would be, so could be more.

But filling the cylinders with a 2:1 air/fuel ratio, that's a lot of fire to burn on each stroke!

Why isn't there some mad billionaire driving a street nitro car?? It's one of the first things I'd build if I ever won the lottery!!