Nitro? Whaddaya mean?

Exactly. All done with RPM. And 2-stroke., Of course its easier to get a little biity engine to rev than a big V10, but even so, thats where the power comes from. You can lekeep pouring nitro and fuel in until the piint comes where the presures in the cylinder cuse a hydraulic lock before firing: Beyond that you can't go, and even that is hopelessly inneficient, as teh gas comes out of te exhaist at HUGE pressure - with most of its energy intact.

More bangs per minute, not bigger bangs, is the real way to get POWER.

And building 7 liter negines that will do 15k RPM and BREATHE at that speed is just too complicated for most people.

Ilmor is a British company. That's where the design comes from. They make the Mercedes F1 engine.

I am pretty sure the Toyota was a Judd at one time.

Not sure who did the Honda.

ILMOR

----- At the end of 1983 Cosworth employees Mario Illien and Paul Morgan decided that they could build better CART engines than Cosworth was willing to fund and they approached Roger Penske and asked for funding. He agreed to pay for the development in exchange for half of the shares in the company. He then sold 25% of that to Chevrolet. A factory was established at Brixworth in Northamptonshire and the first engine was completed in the summer of 1985. The following year the engines took two pole positions and in April 1987 Mario Andretti scored the first victory for one of the engines at Long Beach. It was the first of 86 victories between 1987 and 1993, including six Indianapolis 500 victories and five CART titles.

HONDA

----- Always have been made in Japan, as ne of the Honda family was a keen motorsport guy. The family is not so keen these days.

TOYOTA

------- I am pretty sure the development of that engine was done in the UK. I thimk its prduceed in Japan.

FORD COSWORTH

------------- UK, of course

BUICK/INFINITI

--------------

Yes, I think that is in fact a US engine. The only one. Adapted riad car engine.

I think Nat Phiz is stuck in the past and still thinks they are made by Cosworth! LOL

The F1 engines wouldn't turn the RPMs they are turning if they wer 7 liters. Something that people don't seem to understand is that HP will not go up in a straight line with displacement. As the engine gets larger the RPM gets smaller as the rotating mass goes up. The dragsters are looking for max torque not max HP. Still lots of tech there. Much of it on how to get huge mass flow into the engine and yet still ignite it. Composite rods and pistons, overhead cams, titanium cranks, etc are used to reduce the rotating mass and prevent valve float. Also the 5,000 HP figure is old, I think the last I heard they were at 7,000HP and the better ones are probably well above that and keeping mum about it. Special designed and built drag engines started about the late 60's, I don't think stock blocks have been used since the mid to late eighty's. Maybe earlier.

Ilmore took over the Cevrolet V6 about three years into its life when Chevrolet tired of it. The Judd was the same situation for the Honda. They are second hand engine designs for the Brits to play with. Also note that after the Brits took over, they never did as well in racing after that.

John Force claimed 8000 for his Funny Car which is a Top Fuler with a body over it. There hasn't been a road-derived engine in these divisions for decades.

You really know nothing about the modern Indy car (IRL)series, do you? The series, for around a decade, have been racing moderately tuned road engines in production chassis. Notice I did not say ROAD chassis. Buick and Infiniti are two very different companies. Infiniti is the luxury car division of Nissan.

No, but they are 3.5 LITERS, and still do 18k RPM.

That is not so. What they need is *controllable* torque for the initial phase, and then total power once the tyres have stopped slipping for the later phase of the run.

all other thngs being equal, you can get the same toruqe on the back wheels from a higher revving lower torque engine by upping the back axle ratio..

F1 engines use pneumatic valves. And - not sure - no cams at all.

Probably the only time I bothered to attend a drag race.

Judd said that? No wonder his engines don't win anything anymore!

Look at modren motorcycle engine design for clues.

Watchg out for new indycar engine, with Rover badging.

Its all down to how much money you spend on detail development. Not radical breakthroughs in design.

I talked to the gearbox man at Prodrive once (Subaru WRC champions etc) they said 'we reckoned that gear changes cost us 1.5 seconds a stage, so we designed a box that changed up and down in 60ms. We then looked at variable ratio and full autos, and reckoned the performance gain wasn;t worth the cost'

Thats the way they do things.

Different capacity, different rules to conform to.

Good design of combustion chambers and valva arrangements don't care much how big the engine size is. Narrow included angles make more efficient combustion chambers, but also make smaller valves.

Is it 1.5 liters or 3.5?

It's not very often that the tires stop slipping. Nowdays they spin down the entire race. The almost not quite catch up near the end. Sometimes when the track is very stickey they stop spinning about 3/4 of the way down. Tire spin at the start is controlled primarilly by clutching along with throttle control. If the track is especially slippery they detune the engine, which usually means less nitro is used in the fuel mix.

Two problems with that, one is that you lose considerable power through the drive train. The other problem is that you will need a thrird and possibly a fourth gear. Even though they now use planitary gear drives you loose time and more importantly traction each time you shift gears.

The AA dragsters don't need pneumatic valves. Its not the pneumatic valves getting the RPM's up, rather its the breathing, low rotating mass, and low gearing. The pneumatic valves are used to prevent valve float to ALLOW and KEEP the RPM's up. Since the AA fuel dragsters have no real advantage with that high an RPM pnuematic valves are not needed. Actually I can see some advantage from the lower drag due to the lack of valve springing and cams. I would not be suprised if someone is expermenting with this. I am not sure what the top RPM of these engines are these days, it is probably higher than either of us have quoted.

Another thing about high nitro racing engines. Power and RPM has gone up in F1 due to a large extent the areodynamics of pumping as much air through the engine. In AA dragsters its due the the hydrodynamics of pumping fuel through the engine, and the ignition systems to ignite the very wet mixture. I don't know if you know this but nitro is as easy to ignite as alcohol or gas. Once ignited nitro is a monopropellent, that is it can burn without air, so the richer the mixture the more power you have. Also with 100% or near 100% nitro you are limited only by how much fuel you can pump in without causing hydralic lock. In the 60s you were limited to as rich a mixture as the spark can ignite, notice the huge dual magnetos of the modern dragsters. Of course with such a rich mixture the air fuel mixture is more of a liquid than a gas, this also contributes to the lower RPM's.

1.5 was the old turbo engines. About 1100 bhp in 'qualifying trim' - i,.e. built to last as long as a drag engine does.

Current NA engines were about 800bhp last time I looked.

With an auto box possibly.

Modern racing auto boxes as used in WRC and F1 are about 60ms to shift. Traction control as used in F1 and tuned up for drag type conditions would probably solve the whole issue and make drag racing completely boring.

Not that it is particularly exciting as it is, or F1 for that matter.

Basically whjat you are sayng is that since what is needed is not actual power per se, because they already have more than is actually needed to spin thw eheels all the way to the pots, but a dead simnple setup that will allow massicve torque, so there is no need to use gearing, and not really any partcular power that could be obtained by allowing teh engones to dop e.g. 12k rpm.

In short, never mind the RPM, just fill em up with nitro and buold em like brovck shithouses.

Which is basically what I started out saying.

They are optimised not for power, but for controllable torqe. and ENOUGH power to lsip the wheels all the way :-)

Yes. Exceopt that in F1 there is simply a ;limit to how much air CAN be pumped. In teh ,imit you can fill teh cylibnder at BDC with air at just under (or under race conditions somewhat over, by ram effect and somewehat by tuned exhaust effect) atmospheric pressure. That's it. No nitro. Standard fuel. You have to utilise that oxygen as best you can - that really limits the bang per firing stroke.

If you want more power you HAVE to rev the thing higher, so all engine devlopment is about getting the engine to phsyically hang together at high rpm, and also to allow it to breathe up there. And then fine tiuning it so its not toally 'cammy' and undriveable.

I haven't been in tht area for a couple ofyears, but last time I was,

it was a toss up as to whether the craks and rods, or the valves, would let go first. Mostly it seems to be the valves, as dropping a valve still seems to be the common way to blow up

Not extrapolating, just stating the obvious. Anything that makes an engine perform better is not a crutch but a tool. Sure, engines run on no nitro fuel, but they all run BETTER with nitro. Engines ran fine with gummy old castor but run better with blends of synthetic and castor. Engines run without antifoaming agents, but problems are greatly reduced with antifoaming agents.

Current NASCAR engines (5L?) are getting 800-900hp using pushrods, two valves per and carburetors! These big cars will do around 250mph if let loose. They have to use carb restrictors on the superspeedways and still qualify with 200+ mph LAPS! 1950s technology and gasoline.

snip

Interestingly enough (for me and other "gearheads"), I heard it wasn't until they compensated for the bending of the crankshaft under loads and adjusted their timing that they broke through a performance barrier in Top Fuel Drag Racing. I was impressed but then again, it doesn't take much. :o) It's the total assault on the senses that grabbed me 25 years ago and hasn't let go.

Greg

I made an error here. Nitro is not as easy to ignite as alcohol or gas. I left out not. Especially at such rich mixtures. That is why they have two huge solid state magnetos.

Some Europeans do not understand that the appeal of NASCAR is that the cars are on almost equal footing. So winning is more about driving and pitting skills. However there is some tech getting into these cars. Mostly aerodynamics, engine tricks that get more power with restrictor plates (However any large advances here just result in smaller restictor plates on following races), tires, and suspension especially on the road courses. The large purses now attract a lot of drivers from other venues of racing. Often a driver, especially rookies, are switched with a ringer road racer for the road courses. The better NASCAR drivers usually do as well as those ringers.