Big Wind Blowing

When the Vortec 350 truck engine was introduced in 1996, it represented the pinnacle of cheap but efficient horsepower from the venerable small-block Chevy engine family. Revised cylinder heads with fast-burn combustion chambers and trick intake runners meant wringing every last drop of torque from the aging small-block architecture. And even though the new LS1 Gen III engine would get rave reviews in the ensuing years, it was the innocuous Vortec that quietly piled up by the millions in salvage yards and Internet auctions across the country.

The Vortec 350 can make prodigious amounts of horsepower on the cheap, and a low-buck blower kit like the 142 from Weiand can take that to the extreme on a thrifty nickel. The folks at Weiand took their famous 144 Supercharger kit, designed a proprietary intake manifold for the Vortec heads, and then cut the cost of the rotor assembly to make it more affordable. This also happens to improve longevity, as the 142 compressor design eliminates the 144's Teflon rotor tips.

Here's the meat of the deal: for a hair over $2,200-the street price of a basic Weiand 142 blower kit-you can add 130 hp to a Vortec 350 V-8. (Pricing gets a little complicated when you consider that all Vortecs were fuel-injected engines from the factory and this is carbureted). For our dyno test, we used a GM Performance Parts 350 HO partial long-block, which includes factory iron Vortec heads, cam, lifters, and valvetrain. You'd do just as well, though, to get a salvage motor, as it already includes the hydraulic roller lifters and cam (the 350 HO only comes with flat-tappet hydraulic lifters). Since Weiand is part of the same group as Holley and Lunati, our test engine has the upgraded hydraulic roller cam, pushrods, lifters, and valvesprings.

We started out with a GM 350 HO base motor, which is rated at 330 hp at 5,000 rpm, thanks to a flat-tappet hydraulic cam with modest lift. For our Weiand 142 blower test, it made sense to optimize the engine's breathing capability with a simple swap to a hydraulic roller (Lunati PN 638-54755). This will give us 215/218 degrees duration at .050, and .489-/.503-inch valve lift with a 115-degree LSA. It's a good idea to step up the cam with any blower installation.

As a dyno engine, this 350 HO Vortec mule has a fancy two-piece billet timing cover and a quick-change beltdrive, which helps the folks at Holley/Weiand swap cams in a hurry. It's unnecessary in a street engine, but it sure looks cool. Once the cam was in, we lined up the beltdrive and torqued the retaining bolt to 70 lb-ft. The retaining bolt uses a left-handed thread to prevent it from backing out.

We upgraded the stock flat-tappet hydraulic lifters to a set of Lunati vertical-bar hydraulic lifters. If you use an L31 Vortec salvage core, it will already have the hydraulic roller lifters, which can be reused if they're in good shape. The Lunati lifters are top-shelf, but will set you back around $600-ironically about the same price as a complete, running, Vortec 350 core.