Originally Posted by
ddude2uc
Most of the reason American engines are lower reving is because of typical American driving habits. We don't like the sound and vibrations associated with high revs and we do like torque. Hell, most Americans don't even like to shift gears and thats another reason why we need engines that have more torque, to feed the energy sapping automatic transmission. Torque is created by having a longer stroke and there are limitations on piston speeds and rotational speeds involved with really long strokes having to do with the inertia of the engine components. Americans drive these types of engines because we can. The rest of the world uses smaller higher reving more efficient engines because their gas costs more.
Engines like in your parents van are large displacement engines. They make their power by the tried and true method of having more room in the combustion chamber for the fuel/air package. More package more power. The old saying goes "there ain't no replacement for displacement." These types of engines typicaly have more torque due to a longer stroke required to get that displacement and still get a compact engine size and effiecent fuel burn as well as make American buyers happy. These engines deliver the classic american hot rod experience. Step on the gas and your head snaps back. We like that.
Having said that, the down side of these engines are that they are big and heavy, and generally not as efficient as smaller high reving engines. (all things equal regarding aspiration and construction materials) A smaller 4 cylinder high reving engine is going to produce more HP to it's weight than a comparably equiped V8.
It all comes down to power to weight ratio. Of course you can modify Cameros and Mustangs with even bigger power plants, but you will give up handling. In the case of Nascar you'll notice that while these bigger cars also use V8 engines, and can handle well, those engines are operating at very high RPMs. In general with engineering, if you can operate a system at a higher freqency then you improve efficiency.
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