Ron, Yes it is interesting, lotta fun too. By the way, I have to oversimplify, I can't type.
I agree valvetrain has been the limiting factor, but... F1 engines have taken rotating/reciprocating inertia to the same extreme.
Now when getting back to bottom ends, you hit the nail right on the head. Those dirt car engines (mad dogs? I think thats a compliment
) aren't limited to just ultra-light bottom ends. The Latemodels eliminate the flywheel, the clutch, and the transmission gears, run aluminum or carbon fiber driveshafts and magnesium hubs. Every effort possible is made to reduce rotating inertia for exactly the reason you stated - we don't what the revs to stay up when letting off the gas. The quicker the engine shuts down, the deeper you can drive it into the corner. Likewise, the quicker the revs come up, the quicker it is off the corner. The problem with the big engines is you can't go too light on the crank or the extra torque shocks the tires, breaking traction and reducing forward bite.
Regarding matching engine cofiguration to track length: thats what I meant by my 430 ci engine being better suited to larger, momentum tracks.
Cup cranks are the lightest SB cranks at about 38lbs. They're the same ones used in our 360s.
BANDIT1 - The set-up used to hook up 750 HP & 690 ft/lbs of torque is the same one that has to turn at the end of the straight. Its about balance and momentum.
I think Dominik oversimplified it the best, tires dictate the torque.
Whether circle track or road racing as long as there are turns, acceleration, and deceleration these principles will apply.
Great, all this foaming at the mouth has messed up the key board. Scott a.k.a. Mad Dog