As we mentioned, Dart's prediction for our project engine was 668 hp and-drum roll, please-that's exactly what we got: a peak of 668 hp at 6,000 rpm (668.9 horses, to be more precise). And while the dead-on prognostication was impressive, even more so was the overall performance of our big-bore 509. With its strong low-end torque and deep-breathing heads, the engine quickly started making big power. It crossed the 400hp level by 3,600 rpm and hit 500 by only 4,400 rpm. By 5,100 rpm it was making 600 hp and it kept pulling to nearly 6,500 rpm-that's some serious revs for a big-block street/strip engine and one of the primary reasons we were interested in exploring the big-bore/short-stroke combination.
Maskin, who's had decades of experience building racing engines, was philosophical about the results. Or, to put it another way, he wasn't surprised.
"We've been doing this a long time," he says. "We know what other engines of larger and smaller displacements make with the same basic components, so estimating the horsepower pretty much comes down to the displacement of the combination."
His confidence was reassuring and we were enthused to find our project engine exceeded expectations on all fronts. We already have an idea of what we're going to do with the engine, but that's another story for a future issue.