QUESTION 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?
ANSWER 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.
I have a 1989 Mustang that I have owned since it was two years old. I have used it for everything from transportation to Solo II racing to bracket racing. A few years ago, the engine blew up at a drifting event. The car sat for a while, then I rebuilt the engine from leftover parts and parts I found by keeping a close eye on eBay and at swap meets. I then drove it regularly back and forth to work. My daughters that have been driving for a few years have shown interest in the car (they can drive a stick, unlike other teenagers). We started to take the car to autocross and cruises. We had plans this summer to set it up for the 130- and 150-mph club at the salt flats. Abby was going to try the 130 and I was going for the 150. Last winter, one day driving home, the car developed a big noise in the engine. It sounded like the flywheel was rubbing. Crankshaft endplay was OK. I think what happened is the machinist added weight to the flywheel to make up for the lightweight pistons. It may have came out, is my guess. What do you think?
Forty years at one company is crazy, but that’s the landmark we’re celebrating for HOT ROD’s very unique, devoted, and walking GM part-number catalog, Marlan Davis. Forty years! You know him as HOT ROD’s Tech Editor par excellence—and he’s that, for sure. But Marlan is somewhat of a mystery, even to the staff, as his desert residence in Neenach, California, isolates him from city hustle and bustle, making commutes into Los Angeles a long haul and sightings at the HOT ROD mothership rare.
Ford’s Flathead V-8, the Engine That Gave Birth to Hot Rodding, Is Back in Vogue, and Here’s Everything You Need to Know About It.
Another very good Ford Flathead V8 article from Marlan Davis, this time it’s a source guide for Flathead V8 performance. The article also contains some Flathead Myths courtesy of Tony Baron and a Flathead History Lesson courtesy of Charlie Clark