I just fell upon this article and found it quite surprising. I didn't realize
the tight limitations:

Formula One engines may be no more than 3 litres in capacity. They must have 10 cylinders, with a maximum of 5 valves per cylinder, and must be normally aspirated.

Devices designed to pre-cool air before it enters the cylinders are not allowed. Nor is the injection of any substance into the cylinders other than air and fuel.
Variable-length exhaust systems are also forbidden.

The crankshaft and camshafts must be made of steel or cast iron. For the cylinder block, cylinder head and pistons, the use of carbon-composite materials is not allowed.

800 HP @ 19,000 RPM on Unleaded "Petrol"

Does this imply they are using pump gas of similar octane ~94 RON+MON/2?

Pretty Amazing I thought...and I even found a cool sig. in the process

 

F1 petrol shares many of the 250 odd chemicals that can make up "pump gas", but it's a FAR cry from what you can buy at any BP or Shell pump. There is a range of Specific Gravities allowed, and some teams have fuel blended to the lightest SG allowed. This saves a couple of kilos on a full tank of fuel. Amazing what a few hundred million a year budget can accomplish.

Over 900 hp now, but probably peak is closer to 18000 with max rpm 19+.

183 cube V10 with a bore about like an 5.7 L LS1, but a stroke about 1.56 inches.

4 valves are used by virtually everyone. Pneumatic (air/nitrogen) valve springs.

New 2006 rules coming: 2.4L 90 degree V8s required. Expect them to increase the bores again (because the engine is two cylinders shaorter), and shorten the strokes to push the rpm over 20000. I suggest 21000+ with maybe 4 inch bores and 1.45 inch strokes. That would keep about the same piston speed. Every lb-ft at 21000 is worth 10% more hp than if you made it at 19000.

 

Gee, why stop there? Why not cut them down to two bangers and spin them
to 80,000 RPM!

Hey, I remove tools and a spare tire to shave a tenth...these guys are
picking out molecules to squeeze another lap.

Nice.

 

The higher the number of cylinders allowed, the smaller they can be and the shorter the stroke and higher rpm. An 80K twin might work in your RC car.



It's not necessarily to squeeze in another lap, but's to make the car lighter and therfore faster for all the laps. The volume of the fuel needed for a lap doesn 't change, just the weight of that volume.

F1 is funny about fueling. They rarely fill the fuel tanks so they make multiple pit stops and add just enough fuel for the number of laps (aka "stint") they want to run before the next stop. They can't change tires, so stops are for fuel only.

 

Each team has their fuel formulated by their petroleum sponsor for their specific car/engine, at the beginning of each year. A sample is presented to the FIA at the start of the season for certification testing. The team must then run this "exact" same fuel all year.

 

Cosworth and Ilmor both have experience with OHC v-8s they have made for other series fairly recently, i wonder if that will translate into an edge for them initially.I guess Ferrari does v8s well too[355/360] but those probably arent going to be too similar to the F1 motors.
I dont see these "cost cutting" measures working very effectively, the pinnacle of motorsport is gonna be big-buck hi-tech.period.Remember when FIA grooved the tires to slow them down and they ran faster than on slicks before?
$200 million worth of engineering will make a coffee machine go 300km/hr if they wanted to.

just my random musings.

 

Absolutely! If the money is there, the power, etc. will be there.

My favorite measure of engine efficiency is torque/Litre (or cubic inch) at hp peak rpm. Many high-end engines are very similar in this area. ProStock is a couple % higher (!) than F1 but Nextel Cup is about 9% lower since F1 got into the mid 900s.

If you assume hp peak is about 95% of max rpm for a race engine, that puts the hp peak of 950 hp(?) 3.0L V-10 F1 engine about 18,000. Torque per L there is about 92.4 lb-ft/L. (Yeah, I'm mixing English and Metric units, but I don't yet think in Newton-meters).

If you shorten the stroke and increase the bore to get a 22,000 rpm 2.5L V8, 95% (hp peak) is about 21,000. If they can keep the same torque/L at hp peak, the engine has about 920+ hp. Sure, hp/L is up 16-17%, but (hp peak) torque/L remains the same. I think this is doable for the top teams.

Keeping the same torque/L at hp peak and raising the power peak rpm is how much of the increased power is found in race engines. Mother Nature controls how much wind you can pump, and she's not easily violated.

More random musings.

 

Here's another random thingie...

Do you think the teams will start to cut into the bore diameter as opposed
to cutting stroke?

There will come a time when the stroke is so short, the lack of leverage
will make turning the crank pretty much counterproductive...know what I mean?

I wonder how a 300 KM/h Maxwell House will corner?

 

I don't think the lever arm theory really even applies here.... it seems like it does but dyno tests just don't back it up ever.

BTW Pops.... I though we agreed that the F1 cars are peaking HP in the 17,800rpm range with the way the tach gets there and stays there at top speed, if the HP peak was higher wouldn't the motor accelerate to that point?

Cool thing about the smaller motors making the same torque/Litre at hp peak rpm is that they now have the same if not more HP and now they have more gear to boot due to the higher RPM so the cars should even be faster.... lol good job at slowing them down Bernie!

Bret

 

in order to determine the relationship between bore and stroke on an f1 engine theres a lot of thing to consider. when you consider the stroke being shorter that allows the team more rpms while keeping the max piston speed a constant. the larger bore also allows more airflow and when you consider that the force applied to the piston could be meassured in psi applied across the piston that is to say the greater the surface area the greater the total force applied to the crank as a direct result given a constant cyl pressure. which warrants a look at the relationship of the force and how to optimize it given limits on engine size. but when you consider torque its the force * radius if the force is applied perpindicular to the radius. the force being applied here is from the psi applied to the piston. now changing the radius results in only a change of the lever the change is whatever the change is in the radius. but when you change the size of the bore (larger) the force should increase at a greater rate if you manage to maintain cyl psi. due to the way surface area is calculated you square the radius. this is most of why I think that f1 uses large bores. the last bit has to do with friction and rod angularity. when you reduce rod angularity you tend to reduce the normal force applied on the thrust side of the bore. and friction is simply a coefficient * the normal force. also as a side effect of the extremely short strokes you get closer to applying the force on the crank at a 90* angle. also this allows them to run a longer rod and keep thier pagacking in a size that keeps them happy. another thing of interest is that they probably get to run a pretty darn small journal size and still have plenty of overlap to keep those cranks strong enough.

this is just a few thoughts that popped up while i was reading this. i think most of it is on the right track, but if not correct away. i've never sat down and done the legwork on the math for f1 engines.

on another note, so much for my break from studying for my diff eq test and in case anybody who's wondered or is considering it, taking it in 6 weeks = no fun

 

I don't know if that is a sure way to tell if they are at peak power. If they are not accelerating, that just means that the aero drag is equal to the power output. If the horsepower curve is very slowly increasing (almost flat), it is possible that the aero forces above that rpm would increase faster than the horsepower output. I don't know that this is the case, but it is possible especially since the gearing (and aero package) is likely optimized for something other than top speed.

BTW I recently heard some claims that the Cosworth V8 engine has already done testing at 20,500 RPM.
Dustin

 

The thing usually dictating how much total power they make is how many intake valves they have and how big they are primarily, so the loss of 4 intake valves will not generally help power at all. The hp/liter should be the same or higher though as the 90 degree V8 does not vibrate as much and the crank is lighter and stronger. It should also probably turn a little more rpm but the only way it will make more power than the V10s is if the 8 cylinders can now breath MORE than the old 10 cylinders could and that probably isn't going to happen anytime soon.

The newer engines should use less fuel however and allow a different chassis due to the new tighter and more compact engine which will also be stiffer as well. So in that way the new engine is all good as far as the chassis builders are concerned!

 

With 7 gears to choose from, and 15-20% of the lap time at Indy accelerating to max speed, and max speed determined when power required equals power available, I think the car would be geared to at least reach maximum hp. Otherwise you are leaving something (hp) on the table.

Yep, hp/L will increase with increasing rpm, but torque/L @ hp peak probably will remain about the same, or grow slightly because of more valve area/cylinder. Larger cylinder bores are available with the V8 because shortening the engine approximately 100 mm with fewer cylinders allows larger bores to fit into the same (or shorter) engine length. The larger bores allow larger valves, so there could be more air pumped per 300 cc cylinder.

Torque at the drive wheels, or more correctly, thrust force at the tire contact patch (which is drive wheel torque divided by tire radius), determines acceleration. (Sound of can of worms being opened). If you can increase max power rpm from 18000 to 21000 (16.7%) you can throw 16.7% more gear at it to increase the wheel torque/thrust.

Example: 900 hp @18,000 is 262.5 lb-ft at the flywheel. 900 hp at 9000 is about 525 lb-ft at the flywheeel. If both engines are in a car which can reach 200 mph with 900 hp, and have the same diameter tires, the 18K engine has just twice as much gear ratio as the 9K engine. If the driveline losses are similar, drive wheel torque is the same at that point. If the torque curve shapes vary below peak, wheel torque varies with the engine torque curve, of course.

To carry that a step farther, if you run your engine say 5% past it's hp peak, you might lose 2.5% hp. However, you can then use 5% more overall gear ratio and come up with a net gain in drive wheel torque, as well as have more wheel torque at every point in that gear's speed range. With a one-gear race, like Nextel Cup, you could be quicker with the same peak hp. Perhaps that's one of the reasons for a gear rule.

I suggest that vibration has not been a huge issue as evidenced by the V10 V-angles ranging from 72* to maybe 108* recently. If balance and vibration and lightest cranks were a big concern, wouldn't a boxer (180*) engine be best? Intake and exhaust plumbing as well as width make a boxer impractical, and 2006 rules mandate 90*.

 

They'd mostly run the 90 anyway since everything works out so well but the rule means they don't have to worry about anyone else trying something wider and they don't have to throw money down that hole.

 

Nice discussion. I predict the new rules will not save money and will not slow them down for more than a year, at most. These teams will spend the same whether the rules are changed or not. I'd like to see less retrictive rules. The amount of technical interest would be much improved if we saw engines with different configurations, displacements, types of valvetrain, etc. Sure, there is a fierce tech battle going on now, but it's largely invisible to the general public.

How about 1.5L turbo 4cyl. v. 3.5L 4 or 5-valveOHC NA V-12's v. 5L OHV V-8s?

Rich