Aluminium Motown Block and Heads 427ci Chevy Small Block.

The light grey color and cross-valley ribs are the clues that distinguish the Motown Lite block from iron versions. Like GM's small-block, the Motown Lite has a 9.025-inch deck height and all common small-block parts and accessories bolt right up.

Many things to note here: First, check out the bulging cylinders and front-to-back ribs. The bulges allow for large displacement and carry generous water passages. The ribs add reinforcing strength and promote cooling, as well. Also, the freeze plugs are screw-in type.

Motown Lite blocks come with 4.125-inch bore steel cylinder liners-the maximum bore that still leaves a sufficient amount of steel in the liner. Special O-rings seal the bottom of the cylinders, preventing oil from squeezing up between the liner and block. The oil acts like an insulator, trapping heat; it also can dislodge the liner as the aluminum and steel materials heat and cool at different rates.

World Products will initially offer the Motown Lite with 350- and 400-size mains.

The crankshaft is a Scat 4340 forged steel part that produces a 4.000-inch stroke. It is internally balance prior to installation.

The first batch of Motown aluminum engines will have billet steel, splayed main bearing caps (seen here). The engine also will be available with nodular iron main caps.

World Products wouldn't divulge the specs of the camshaft. We do know that it's supplied by Crane and is designed to give what Bill Mitchell says is "a great sound, great idle quality and great upper-rpm performance."

Forged aluminum pistons from Wiseco fill the engine's 4.125-inch bores and deliver an approximately 10:1 compression ratio--a great compromise of squeeze and pump-gas compatibility.

The rods are from Manley and they're H-beams made from 4340 forged steel.

A high-volume Speed-Pro oil pump is covered by racy looking Milodon dump-sump oil pan.

The all-important cylinder heads are more World Products castings. They're the Motown 220 heads that are cast so that the ports have fewer irregularities; i.e. they don't have to be ported for optimum flow.

The base 427 engine comes with 64cc chamber volumes, although heads with 72cc volumes are available. The chambers are accessed via Manley Sever Duty stainless 2.055-inch intake valves and 1.6000-inch exhaust valves.

Like the block and heads, World casts their own intake manifold, too. In the case of our aluminum 427, it's a single-plane design with "spider" dividers at the base, giving the engine the benefits of high-rpm performance and low-rpm power.

An 870-cfm carburetor is used. It's a modified Holley carb that is designed to provide great low rpm, "cruise night" performance without loading up.

The completeness of the crate engine package extends to the inclusion of many accessories, including a race-legal balancer.

World Products also installs an HEI distributor on each engine. And because each engine is dyno-tested prior to shipment, the engine is timed correctly, too.

Ignore the valve covers-they're for a different engine. Our visit to World Products was early enough in the development of the Motown aluminum engine that the correct valve covers weren't available. Nevertheless, what you see is what you get out of the crate. World says the engines is good for about 535 hp, 540 lb-ft of torque, and 6,300 rpm. We know they sandbag their power numbers, too, so we wouldn't be surprised if the true numbers were a little higher. Not bad for an assembly that ways a mere 435 pounds!