Fed up with all the mild pump-gas "street motor" buildups most magazines bang out every month? That's our bread-and-butter, but every now and then you have to step it up. That's what we've got here.
Recently we had the chance to follow along on a brutal big-block buildup that takes advantage of the latest aftermarket technology to make more power than a tunnel-rammed Pro Stocker from the '70s, while costing little more than a premium crate engine. Steve Brule of Westech Performance in Mira Loma, California, was in the process of building up a production Chevrolet four-bolt-main 454 block in an attempt to crack 900 hp on muscle alone. That means no nitrous or supercharger, just motor. We knew the potential was there, but performing that feat with a nonstroked 454 displacing "only" 476 cubic inches, relatively mild 13.6:1 compression, and a single four-barrel carb on a single-plane manifold seemed a lofty goal, even on race gas.
Despite our skepticism, our man Brule managed to crest the 900 mark right out of the box, showing 904 hp at 7,500 rpm and 679 lb-ft of torque at 6,300 rpm. A little tuning found an additional 7 hp for a 911 reading at 7,500 rpm and an additional 4 lb-ft of torque with 683 at 6,300 rpm. But what did it take and how much did it cost? Guess you'll have to read on to find out.
Suck It Up
The primary function of a beltdriven vacuum pump is to stabilize the piston rings so there is only pressure on one side of the compression ring, as well as to reduce crankcase windage for better oil control (more power). The vacuum pump creates an atmosphere inside the crankcase ranging anywhere from 13 to 15 inches of vacuum on a wet sump (higher on dry-sump systems) and literally sucks out any blow-by inside the crankcase to promote a better ring-to-cylinder-wall seal. Conventional engines that don't utilize a vacuum pump generally have pressure on both sides of the rings, which not only hinders the ability of the rings to seal against the cylinder wall, but also poses resistance to descending pistons, robbing more power. It's important to note that while many applications can benefit from a vacuum pump, it's best suited to attempting to extract every last bit of power, and can be worth up to 20 additional ponies.
