The advancement of GM's LS engine platform is comparable to--and perhaps just as important as--the development of the original small-block Chevy. Introduced in the '97 Corvette, this "new" engine family replaced the traditional small-block and big-block Chevy engines from GM's powertrain lineup. It's currently found in numerous cars, SUVs, and trucks and is considered to be the GM V-8 engine of the foreseeable future.
Designed with the same 4.400-inch bore centers as the Gen I and Gen II small-blocks, the LS-series design, which includes a deep-skirt block and six-bolt main caps, has proved itself capable of supporting tremendous power. Not surprisingly, performance enthusiasts and racers alike have embraced the LS--particularly C5 and C6 owners who are packing various configurations of the engine under their hoods.
But just because the LS wasn't factory installed in one's Corvette doesn't mean it can't be used to power up an older car. The compact dimensions, lightweight aluminum block and heads, and burgeoning retro-fit market make the LS a smart, contemporary choice. And with a variety of carburetor swap kits, it's easy to drop an LS engine in a pre-EFI car.
The idea of building a powerful LS engine for an older car intrigued us, so we started bending the ear of World Products' Bill Mitchell. World recently introduced its own version of the LS engine in the form of the Warhawk cylinder block and heads. Although GM offers a number of production-based crate engines, Mitchell saw an opportunity to carve out a niche of the LS world for his company.
"The LS engine is the performance engine of the future," he says. "We think there's room for a high-performance-oriented family of components that is suitable for the street or strip."
Like World's Motown small-blocks and Merlin big-blocks, the Warhawk is based on GM's design, but with enhancements designed to improve strength and support greater power. It also has provisions for six bolts per cylinder head, which shores up one of the LS engine's few shortcomings: head sealing under very high load or boost pressure. GM Performance Parts' LSX block comes with six-bolt provisions, but it's currently available only in iron. The Warhawk block is a lighter-weight aluminum piece with iron cylinder liners.
Here's a quick look at the Warhawk's key features:
* Made of A357-T6 aircraft aluminum alloy
* Billet-steel main caps with APR 200,000-psi main studs
* Reinforced block design with six-bolt cylinder-head capacity
* Priority main oiling circuit
* The water jacket surrounds the cylinders and separates them from the head-stud holes. This increases the strength of the cylinder area and allows the studs to reach deeply into the block
* Two deck heights are offered: 9.240-inch (GM production height) and tall-deck 9.800-inch
* Can accommodate 4.000-inch and 4.125-inch bores (depending on the sleeves and requisite support)
* Motor-mount provisions from both early- and later-style engines
* Weighs only 133 pounds with the sleeves and main caps installed
When figuring out displacements, the Warhawk's 9.240-inch-deck block allows for a 4.000-inch stroke, which yields a maximum displacement of 404 ci (with 4.125-inch bores). The 9.80-inch deck enables a whopping 4.500-inch stroke, which, when combined with 4.125-inch bores, delivers a big-block-like 454 cubes. Because the tall-deck block pushes the heads farther apart, spacers are needed to run production-type intake manifolds. To anyone who's familiar with World Products' capabilities, it should come as no surprise to learn the company offers the spacers, as well as heads themselves. In fact, World manufactures two LS-style heads: the cathedral-port LS1X heads and the rectangular-port LS7X.