I have two questions I believe are related:
- Why do LS engines rev higher and reach peak horsepower and torque at greater rpm than a traditional small-block with similar cam-duration figures?
- Why do LS engines not seem to benefit as much as a traditional small-block from the addition of long-tube (equal-length) headers?
Back in 1955, you (or your grandpa) might have posed a very similar question: “Why does that new-fangled small-block Chevy make more peak power and torque at a higher rpm than my trusty Flathead Ford?” The short answer: “Technology marches on.” Broadly speaking, modern Gen III–and–later LS engines benefit from nearly a half century of progress since the original small-block’s debut, many of which are thanks to the tribal knowledge gleaned by racing traditional Chevy V8s. Racers demand efficiency, but so do ever-tightening emissions and mileage standards. Some of the GM engineers who helped design various aspects of the LS engine were deeply involved in performance and racing, either in their “off” time or as the result of previous assignments to Chevrolet’s official racing programs.
Read the fascinating facts behind the answer here