World Products 427ci Small Block Chevy

World Products' all-aluminum Motown small-block is the "low carb"alternative

From the February, 2009 issue of Super Chevy
By Richard Holdener

Link to Origional Article

Just as your doctor has told you excess weight isn't good, so it goes for your Camaro. Never the most featherweight of muscle cars, Chevy's nose-heavy pony car benefits greatly with every shed pound-especially up front.

A fiberglass hood will shave some weight, as will a set of aluminum heads. But if you really want to lighten your Camaro's front end, World Products' new Motown "Lite" aluminum small-block crate engine might just be the ultimate weight-loss plan.

Although World Products has been offering Motown engine assemblies for a couple of years now, it only recently started building them with their all-new aluminum block. Compared to the standard iron block, the alloy version weighs only about half as much.

"With this block and aluminum heads, you get an engine that weighs only about 435 pounds," says World's Bill Mitchell. "That won't even compress the front springs on some cars."

Like the iron version, the alloy Motown Lite is strategically beefy. The 357-T6-cast bare block (with main caps and cylinder liners installed) weighs just 100 pounds-an iron Motown block weighs about 195 pounds.

Besides its light-grey aluminum coloring, the most obvious deviations from the World Products' iron small-block or, for that matter, GM's own small-block Chevy, is the horizontal strengthening ribs along the cylinder banks. They add strength and are connected internally to serve as cross-feed oil galleries.

The extra meat in the block's casting is mostly on the inside, so all the Chevy small-block accessories, from intake manifolds to fuel pumps, bolt up as with a stock engine. The extra metal, however, allows World Products to slip in some thick cylinder liners and create Mitchell's signature big-displacement torque monsters. A 427ci displacement is the maximum with a 4.000-inch crank (the iron block can yield a 454 displacement).

One of the block's other unique features is a series of O-rings at the bottom of the cylinders. They help hold the liners in place and prevent oil from squeezing between the liners and block - then bane of many aluminum engines.

"When it gets up there, the oil acts like an insulator and prevents the aluminum from transferring heat," says Mitchell. "It also helps dislodge the liners."On top of this lightweight foundation, World Products bolts on its time-tested roster of power-building components - each selected to help move air efficiently through the voluminous passages. Motown 220 heads, named for their huge 220cc intake runners, have equally large 2.055/1.600 valves.

Straddling the heads is Motown intake manifold topped by an 870-cfm carb. Technically it's a single-plane intake, but a unique "spider" design allows the engine to make useable low-rpm power and torque. This was important as Mitchell sees this engine as much as a street performer as a race engine.