That's just the static part. Now throw on 16 lifters pushing 700lb springs with a 1.5 rocker ratio, driven by a crankshaft that's jumping all over the place, twisting and untwisting as it bends and generally does the Watusi.

Metal doesn't begin to work unless it is stretched or squished. The impression of rigidity that we get looking at parts lying static is totally wrong.

I'd be willing to bet that driving the camshaft from both ends or maybe from the middle would show power gains on high perf engines. I am sure that's one reason why the cams are getting larger and larger in diameter, seeing how the torsional rigidity increases as the cube of the diameter increase.

R.