Don't forget the pneumatic valve actuation in the F1 engine and the use of MUCH stronger materials used in the entire assembly.
-Steve
Our F1 valvetrain was good for about 23krpm, which we never took it to except on the rig. For a couple races in 2000, we shortened the stroke even further than it was, and ran at 20krpm. Yes on the pneumatic springs(at extremely high pressure, if I remember correctly from my F1 days) plus very lightweight titanium valves. One more thing that astounded me: zero valve clearance. Yes, they are designed to touch the piston at max rpm!
In contrast, NASCAR valvetrains are massive and very compliant, thanks mostly to their insistence on using pushrods(cam in block). It's a catch22: to design a stiffer valvetrain requires large diameter, stiffer pushrods, which add to the weight problem, at the worst place possible: very far from the spring pack. As a consequence, modern profiles are designed to "toss and catch" the valvetrain. When they first discovered this was happening, they designed the spring package to eliminate it, since it was destroying engines. Later, they put some science behind it and controlled it. Now they're intentionally built that way, instead of accidentally. Short tracks will take the engine to 9,500rpm all day long, right before the braking point, which is much harder on the engine than longer, high speed tracks that don't venture much about 8500rpm or so. Few hundred rpm makes a huge difference in longevity, and I'm still amazed they stay together for 500 laps. One of my buddies at Yates once told me whole car is pretty much trashed after a short track race, not just the valvetrain and body.
