F1, trickle-down, etc.

[James Montebello]

On Sat, 29 Sep 2001, Wild Thing wrote:
>The F1 engines are not running "insane" piston speeds. Look no further
>than a 100cc kart engine. They have a 5cm stroke and rev to 24000rpm,
>while F1 engines have around 4cm stroke and rev only 18000rpm. And kart
>engines have mandatory steel con-rod, none of those $$$ materials that
>the F1 engines use. What impresses me is the valve acceleration that the
>F1 engines run. The valves move so fast that valvesprings are simply to
>slow to close them (a spring takes time to decompress even without load).

Yes, and 5cc model airplane engines run piston speeds that are
higher still.  When you reduce the size of something, you lose mass
far faster than you lose strength.  An F1 cylinder is 300cc, not 100cc.
The stroke may be the same, but the piston weighs quite a bit more than
the kart piston, so the forces involved are considerably higher, even
for a slower engine speed, and the specific strength of the kart pieces
will be higher.  By any measure against production engines, or even most
car racing engines, these piston speeds are very high indeed.  The fact
that there are even higher speeds out there doesn't alter that fact.

The valve acceleration wouldn't be possible without the pneumatic valve
systems currently employed.  Renault is rumored to be using a camless
valve system in their current F1 engine.  If this is true, and becomes
commonplace, there's yet another place where F1 engines are leading the
technology stakes.

james montebello

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