Archive for 20 k rpm

20,000 rpm not in F1

Posted in Noteworthy, Tech, Transport with tags , , on November 9, 2009 by Apollo

While it seems a bit silly for a business that sees fines of over £100 million as little more than petty cash or small change to speak of “cost saving measures”, F1 development rules still means that achievements are made that we may be cheated of seeing.

I had anticipated seeing engines running to 20,000 rpm in the 2009 season, but the rules outlawed this figure, and capped them at 19,000 rpm in the name of economy.

However, as anyone with an ounce of engineering knowledge will realise, to run reliably at 19 k, you have to be able to perform unreliably at higher numbers, and 20 k is only some 5% more in terms of revs, although that same engineering knowledge will also tell that the energy involved will increase by something more like 10%, and that doesn’t merit the same use of the word “only” that 5% merits.

In a 4-stroke engine this is particularly significant, since it means the reciprocating parts – in particular the pistons – also carry that amount of additional energy, and the con-rods have to haul them to a full stop and reverse their direction 333 times every second, or every 3 ms. These really are speed and energies you wouldn’t want to be too close to when a rod lets go, and the pistons decide to leave the engine.

With that in mind, I was intrigued to see a Cosworth engine test at 20 k, although it may be significant to note that the test was not maintained once 20 k had been reached, but was terminated almost as soon as the figure was achieved.

Piston engines can go much faster, but not as car-sized V8 or V10 designs. These engines are tiny by comparison and can be found in models, and turn at ridiculus speeds by comparison, many times that of their larger brothers, but then again, they are very, very much lighter, but can still be built of exotic materials – they use so much less!