RPM ?????

[xl0427]

I had a night to think about this question.
Which will be the rotation limit that the engines of formula1 will be able to reach?

To that if it knows, the engines of the BMW reached 22000 RPM.

22000 rpm - 367 rps

183 complete cycles per cili.

1 cycles - 0,0054 seconds


1 cycle is four strokes. what it gives, 0,00135 seconds for stroke.

The time that you delayed to read this post, the engine to the 22000 rpm, completed 10000 rotations.

My question is:
Which the limit for the rotation of an engine of internal combustion?
We have to have in account the advance to the ignition and the inercia of all the components?

[Monstrobolaxa]

Wel i think the question is interesting....in 2002 when BMW passed the 19000RPM barrier I read an interesting article written by Thiessen, explaining why the the 19000RPM barrier was so importante.....and according to him a 4-stroke internal combustion engine has a theoretical limit of 18,500RPM. This is also mentioned in the Peter Wright book "F1 TEchnology" but in this book he says the theoretical limit is 18000....500RPM less.

[Racer-X]

Another problem related to high revolutions is the combustion. A fuel has to burn quick enough in order to follow the engine requirements. The fuel suppliers in F1 are developing fuels to burn quicker and the flame speed of a fuel is a very important factor

Also the amount of force applied in the engine parts are critical. As quick you apply force to the pistons critical became the connecting rods, bearings, etc.. It is not only the amount of force, it is also the speed the force is applied.
One important parameter when you design an engine is the dP/dα (Chamber Pressure/crankshaft degrees ) of the combustion chamber during the combustion process.

[Guest]

Which kind of hydrocarbons can be used to improove the flame speed of the fuel?
Does it can damege the engine?
Adding this kind of component will increase the maximum RPM?

[Guest]

I have another point to add; another limiting factor is the valvetrain. Because, despite the pneumatic valves being able to return much faster and more consistently, there is still a limit on the speed at which the engine can run, while keeping the valvetrain in perfect harmony with the rest of the operations of the engine. One solution that could bring advancement is the 'Renault-made-famous' electro-hydraulic valve system. I'm not sure how much of advantage this will bring to RPM-ability, but its variablity is the main factor.

Also, on the point about fuels, it is partly the calorific value of the fuel that can govern the speed at which combustion can occur. And, as such, the regulations in F1 about octane levels and calorific values restrict that combustion-speed. However, as someone has mentioned, uses of other substances such as Hydrocarbons can be used to further refine the mixture and hence help the ignition process.

rob

[Guest]

I haven't seen anything regarding calorific values limitation on the technical regulations in the FIA web site..... Octane Number yes, 102 max for RON and 85 min for MON but this have no relation with flame speed or RPM.

[roy131]

Well, I agree that the limitation of engine RPM now is on the flame speed. And to make it faster, there are some ways to do besides improving calorific value. They are to boost the fuel injection pressure and/or to enrich the mixture.

[thedrik]

The fuel burning speed issue is very complex. There are also valvtrain control issues. Presently there is a point of diminishing returns by trying to cycle the engine faster. Yes, it is true that more work per area unit time should deliver more power, but the greater engine speeds may not let the air/fuel mixture expand at the correct moment to deliver the greatest push on the piston when at the optimum position(s).
If I were building and F1 engine, I would take a look at the best fuel I could legally get by with, and what I could possibly do to get this fuel to light, burn, and deliver it's heat within it's confines of the cylinder in the shortest time possible. Making this qualified judgement at what cycle speed this fuel can effectively deliver a quality burn with the compression allowed (if any rule)...taking into account bore diameter, stroke, rod length, and a couple other factors. Based on thisfuel finding, I would go to work with the "Spintron", and run tests to see how aggressive the valve motion could become at speeds within the fuels capabilities, and limit my valve motion vs. engine speed in accordance to my fuels capabilities. I would be more concerned on working with the overall average power level within a rpm range than some perhaps peaky high strung engine. Not to say that moving the whole torque curve up 1000rpm from 19,000 to 20,000 rpm for instance wouldn't be beneficial...it might be... but producing a driveable/manageable engine with a flat torque curve is probably what drivers want most.
tkr60411@aol.com

[Becker4]

perhaps this is why renault can compete so well with an engine that has less hp than other manufacturers . . . . there peak hp might be much lower, but it might be distributed much better and with a flatter torque curve, the drivers can use the power much better. just a thought.

[thedrik]

Becker4 , Your thought is mostly correct from my experience. It seems managable predictable driver friendly power is key in the overall performance package.
Case in point, the 2003 Kawasaki GP Motorcycle... Extreme power levels, super rpm capabilities, but totally rider un-friendly. The power comes on so hard, and on such a radical "right-now" surge, that no rider has been able to ride it successfully. Needless to say, Kawasaki did a little re-engineering for 2004 to make more manageable rider friendly power, and rider feedback has been much better. On two wheels, the effects of unmanagable engine power are magnified probably ten-fold over that of a 4 wheeled vehicle, but the effects of such are still present.
I don't know what the rules are in F1, but it would seem that Electronic Traction Control may be in use if legal. It would make the peakiest high horsepower cars more tractable. tkr60411@aol.com

[Enzo]

Another point you didn;t mention is the friction which is very much critical for the operation of the engine. Friction power (power loss) increases proportional to the square of rpm, so while the rpms is increasing the friction is double increasing which means that at some point the energy released by the air-fuel mixture will become inadequate to compensate with the very high inertia of the moving components.

Apart from that, think aout it a little. We are not making a rpm competition. Yes BMW may have a little more rpms than Ferrari or Honda but you actually don't know the BMEP figures at that point so you don;t know the actual power released by the engine. (in fact you don;t know the thermal, mechanical and volumetric efficiency of the engine at that point).

[Racer-X]

I've read somewhere at the beginning of the year that BMW and Petrobas were developing special hydrocarbons in their fuel to reduce friction, specially in the first piston ring, increasing the RPM and power and protecting the engine at the same time.

[rodders]

on this topic did anyone see the onboard shot of Rubens where the tacho was showing his shift patterns and revs at Bahrain ?

I am sure the revs were above 20,000 in a number of instances , around about 20,400 if my memory serves me right !!!

[Monstrobolaxa]

I've said it previously in another thread......don't believe everything the TV tachometre shows......the number is based on an acoustic analysis of the engine...there was an article about this in the 1998 May edition of Racecar Engineering (if I'm not mistaken)....the programs can be very efective but diferente engines have diferente sounds.....so the program can have glitches and give strange readings.

[marcush.]

good quote,they are not in a max RPM competition nor are they in a max power competition either.
What you need is a efficiant way to propel the thing in the shortest timescale from start to finish and that´s it.
so fuel consumption is very high on the list as you could save seconds in the pits by not having to refuel as much...extracting more power leads to more losses ,leads to more heat you have to get rid off ,bigger coolers bigger ducts ,less aero efficiency...so actually a stronger engine may fire back in making the whole package more inefficient.
A major breakthrough would be to reduce frictional losses even more as this would reduce heat dissipation ,and so reduced oiltemps and watertemps,giving more scope for aeroefficiency.
It is always the same ,bigger is not always better.... and as all those boffins are not dump ,I´m sure in internal discussions max power figures are not really a topic.