With our thinking in alignment with Maskin's, we embarked on an engine-building project that would test his wisdom. We were looking for a 500-plus inch engine that would offer good dual-use duty on the street and on the drag strip. Maskin pecked out a few numbers on his calculator and a figured a 509-inch combo, with 4.500-inch bores and 454-standard 4.00-inch stroke, would do the trick.
"Based on the 400-inch SHP (Special High Performance) engines we build, it should make 668 horsepower, with all the torque you can use," he says. "It's a simple combination, too, using nothing but off-the-shelf parts."
With Maskin's recommendations, as our blueprint and his in-house engine builders our guides, we set up shop at Dart's suburban Detroit headquarters and documented the combination's assembly from the installation of the first bearing to the final pull on the engine dyno.
The basics include:Dart's Big M iron cylinder blockDart's 310cc aluminum Pro1 cylinder headsEagle 4340-forged crankshaftEngine Pro H-beam connecting rodsJE pistonsComp Cams hydraulic roller camshaft and rocker armsDart single-plane intake manifoldDemon 850cfm carburetor
Although our 509 engine combination seems straightforward enough, it's not something Dart stocks in its warehouse. In fact, the company doesn't sell crate engines per se, but offers a variety of short-block assemblies and the service of custom engine builds. To mirror that, we've divided this story into a pair of installments; the first focusing on the big-bore, short-stroke short-block and the second on the remainder of the engine assembly and dyno testing.
What that means is you'll see the inside of the short-block in the accompanying photos, with insight into the attributes of the Dart block that support such a generous displacement. You'll have to pick up next month's issue to see whether this Dart engine hits the bull's eye of Maskin's 668hp target.