High revving engines - endurance
High revving engines - endurance
(OP)
Hi!
Can someone explan why F1 engines break after only few hundred miles, I mean what parts are the weakest link and why do they fail? What is the most often reason they broke?
I read that some civil sport car engines (Audi R8 V10 for example) have average piston speed higher than F1 engine. Why don't they break so fast?
Thanks!
Can someone explan why F1 engines break after only few hundred miles, I mean what parts are the weakest link and why do they fail? What is the most often reason they broke?
I read that some civil sport car engines (Audi R8 V10 for example) have average piston speed higher than F1 engine. Why don't they break so fast?
Thanks!





RE: High revving engines - endurance
An F1 engine is very different. It has just 3.0l and makes around 950hp, with a rev limit of oh...18,000
Consider what both engines each weigh that you are comparing also.
Perhaps this will start to explain why they break.
If you have never seen one in person, you should have a look, they are also disappointingly small. All the more reason as to how they are so impressive from an engineering point of view.
Also, piston speed and max piston acceleration at tdc so be looked at, lot of reading there...
G-forces within an F1 engine are insane, with hot bike engines a close second. Same goes for piston velocities.
Brian,
RE: High revving engines - endurance
http://www.eng-tips.com/viewthread.cfm?qid=85349
Brian,
RE: High revving engines - endurance
F1 engine (2003 BMW F1 engine) - at 19000 RPM, average piston speed is about 25m/s, max. piston acceleration is around 10000g.
Audi R8 V10 5.2L 560hp - at 8700 RPM, average piston speed is 26.9m/s, max. piston acceleration is around 5000g.
Ferrari 458 Italia V8 4.5L 570hp - at 9000 RPM, average piston speed is 28.2m/s, max. piston acceleration is somewhere around 5400g.
We can see that Audi and Ferrari have greater average piston speed than F1 engine. What does this fact tell us in terms of reliability? Why so many car magazines quote this number if it is greater than F1 engine numbers.
Now, it is clear that F1 engine piston has a lot greater acceleration, but it would be nice if someone have piston mass numbers for those car so we can calculate real force that is acting on piston mechanism.
It is obvious that Audi and Ferrari have bigger engines with less hp than F1 and they could be cooled easier because of that but it would be nice if someone can answer what is the most common failure in F1 engines and why?
RE: High revving engines - endurance
One of the main problems with such speeds is keeping the big ends round, and the hydrodynamic oil film complete. - Bare in mind doing all this with minimum conrod material.
Pneumatic valve trains are another weak point, the gas escapes and the valve train suffers.
Brian,
RE: High revving engines - endurance
The need for light weight, and especially for low reciprocating & rotating inertia, will drive extremely light, high rpm solutions, in F1 and other racing environments. This will result in high g forces, that are readily met by the appropriate design solutions.
RE: High revving engines - endurance
There are 2 basic areas where failure occur - the rotating assembly and the valvetrain. I'd suspect that valvetrain failures are the most common.
RE: High revving engines - endurance
RE: High revving engines - endurance
Cheers
Greg Locock
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RE: High revving engines - endurance
Brian,
RE: High revving engines - endurance
RE: High revving engines - endurance
RE: High revving engines - endurance
Running in simulated city/traffic conditions is not necessarily an easy ride as there may well be more coolant and oil temperature variation and rich running during accelerations.
Bill
RE: High revving engines - endurance
- Steve
RE: High revving engines - endurance
As far as F1, as has been mentioned, the rules dictate the design. Currently, each driver is allowed 8 engines per season. The rules also dictate the material for each major component (mostly NOT exotic materials), as well as the lack of most 'advanced' features such as variable timing and geometry.
The load cycle is pretty severe for F1 too. Full load/speed is often not as detrimental to components ans a wide load/speed cycle such as an F1 race where the engines are constantly cycled from full load to full braking load amidst various environmental conditions.
RE: High revving engines - endurance
In a nutshell, ultimately the rules limit theoretical maximum performance, and the teams strive with each other to approach that theoretical maximum, by expending the all funds they have available, as wisely as possible.
RE: High revving engines - endurance
I agree, no matter how tight the rules, someone with the desire and budget can get an advantage from investing more in development within the rules or by finding ways around the rules.
A case in point. In a turbo class with maximum allowable boost, some manufacturers spent a lot of time developing the best location in the manifold for the pressure sensor to get the lowest possible reading. Things like in a side chamber with the entrance facing away from direction of airflow.
I think one may even have created a side chamber with a somewhat restricted inlet to it and a bleed of from it. I think they got disqualified for a few years when caught.
Point being that extensive testing for the best legal position costs.
Regards
Pat
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RE: High revving engines - endurance
RE: High revving engines - endurance
This is more true with a designer/constructor's formula, like F1, where rules makers may not anticipate unintended opportunities for innovation, than it is with spec or preparers' formulas, like NASCAR.
Al
RE: High revving engines - endurance
the requirement in F1 is pretty straightforward: as high as possible a power output as possible with as little weight as possible that lasts a full race and some preliminary training time. anything longer will result in either less power or more weight or both and less change to be successful in the race.
to get to that point calls for extensive testing, careful design, QC and exotic materials, but all that effort in the end is geared towards that one goal: power combined with lightness.
RE: High revving engines - endurance
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RE: High revving engines - endurance
RE: High revving engines - endurance
RE: High revving engines - endurance