With 454 cubic inches, 600 horsepower and 575 lb-ft. of torque, there’s no reason to believe anything else than the engine in question is Mark IV-type big-block. The displacement. The torque. It all adds up, right?
We’re not talking about a hopped-up vintage Rat motor. We’re talking about one of World Products’ overachieving MoTown-based small-blocks – an engine based on the Chevy small-block, but with World’s own cylinder case casting. (The New York-based manufacturer also casts its own big block case that goes by the name “Merlin.”)
Consider that for a moment: In a mid-year Corvette or C3, this engine offers the same road-wrinkling torque as a big-block, but without the front-end weight penalty. Fewer pounds on the nose means better weight transfer to the rear axle, for better launches and better overall handling. And for C4 owners, this combination is a great alternative to the factory small-block, particularly the lower-powered pre-1990 examples. It is compatible with fuel injection, too – just pop off the intake manifold and carb and replace them with your favorite injection system. Sure, you’ll have to source a controller, too, but that’s easy.
As is often the case, raw dyno numbers don’t tell the whole story. There’s a lot more to the Limited Edition 454 than cubes and a cam. For starters, it’s a small-block that didn’t originate in one of the General’s foundries. It’s one of World Products’ MoTown castings and also wears the company’s MoTown aluminum heads. The engine is also part of a six-step crate engine roster developed by World Products. Each level is signified by features such as a hydraulic or solid-lifter camshaft, increased compression, greater power and, of course, increased prices.
At the entry level is the “Daily Driver” series, followed by the “Cruiser,” “World Class,” and “Hardcore” crate packages. After that comes the “Limited Edition,” and, finally, the competition-only “Drag Race” engines. As a Limited Edition engine, our 454 project engine comes with solid roller lifters, 10.5:1 compression, high-flow aluminum cylinder heads, and a Dominator-type carburetor. It is suitable for the street or strip.
There are numerous options, power levels and displacements within some of the categories. Suffice it to say there are more choices than we have space to outline on these pages.
Like the other small-block engines in the World Product’s roster of crate engines, the company manufactures the block, heads and intake. World’s MoTown block and heads are cast to beefier specs than standard GM parts. The four-bolt MoTown block has one-inch-thicker front and rear bulkheads for added strength. There’s more iron around the cylinders, too, than a stock block. This allows for expanded coolant passages and head bolts that go in blind, meaning they don’t go into water – important considerations when you’re overboring to 4.000 inches and beyond.
Nodular iron main caps are used on some MoTown engines, but others – like our 454 – used splayed, billet steel four-bolt caps. They are cinched down with half-inch bolts on the outside and studs on the inside.
The crankshaft itself is internally balanced. Externally balanced cranks typically wear weights attached to the front and/or rear of the crankshaft, while an internally balanced crank has material added to the individual counterweights. An internally balanced crank is likely to last longer and make the engine run more smoothly.
Like the engine block, the MoTown heads are based on the production small-block castings, but they’ve got bigger water passages and some extra material to compensate for them. They bolt on like stock heads, though, and utilize all stock-type hardware and valvetrain components.
With its big-block-style output, the 454 obviously makes efficient use of the passages in new, 23-degree heads from World; each with 215cc intake runners, which are about 25 percent larger than a stock small-block’s (170cc) runners – necessary to feed the big displacement.
“The cubic inches won’t do it [make horsepower] alone,” Bill Mitchell says. “You’ve got to follow through with cylinder head flow. Remember: Horsepower is the product of torque divided by 5,250 times rpm. A high-flow cylinder head is going to give you more rpm and, consequently, more power.”
Complementing the volume of the intake runners are 72cc fast-burn combustion chambers. The bean-shaped chambers promote quicker light-off of the air/fuel mixture and more complete combustion.
Like everything else, the valves are big. Measuring 2.080 inches on the intake side and 1.600 inches on the exhaust, they’re actuated by a solid lifter cam specific to this engine combination (Mitchell keeps his cam specs close to his chest). It’s a quick-acting, deep-breathing cylinder head/valvetrain combination that allows the 454 to rev to more than 6,000 rpm.
“On the face of it, it seems like a simple concept: the bigger the air pump, the more power you get,” Mitchell says. “That’s true, but ensuring the power is usable, dependable and consistent is the trick. We’ve spent countless hours developing engines that not only deliver big power, but do it reliably.”
Air enters the engine through a World Products-modified “Hardcore” Dominator rated at 1,050 cfm. It flows into a single-plane manifold that has passages designed to support good street-driving characteristics. Yes, it too, is a World Products-designed part. The “turtle”-shaped floor of the manifold is what makes it usable on the street or racetrack. Our experience with World’s big-inch, big-power engines bears out their claim for the manifold.
The 454 engine’s remaining components are a collection of the performance industry’s best: Manley, ARP, Melling, Moroso, Mahle, Speed-Pro, and so on – your basic who’s who of the high-performance aftermarket. The completed assembly includes plugs, wires, an MSD Pro Billet distributor, and a harmonic balancer – everything but a water pump, flywheel, and oil in the pan.
“Shipping regulations dictate we can’t send engines with oil in them,” Mitchell says. “But we dyno test and tune every engine with fresh oil, then drain it before crating up the motor.”
All of World’s crate engines come with a two-year warranty, which definitely provides peace of mind that generally doesn’t accompany other manufacturers’ engines – nor that home-built special you attempted a few years ago.
We love the fact that the Limited Edition 454 is everything a big-block could offer packaged in a small-block envelope. And with 600 horses on tap, it delivers much more than any Rat delivered by Chevrolet.
The Aluminum Alternative
If there’s one thing we’ve learned after repeated trips to World Products’ build center on Long Island, New York, it’s like visiting a roadside fireworks store. There’s lots of great looking noise makers on the shelves, but you can’t help but ask the guy behind the counter, “Where’s the good stuff?” He beckons you to the backroom, where an arsenal only a few dynamite sticks short of World War II is stacked to the ceiling.
At World Products, asking for the good stuff directs you to things like an aluminum casting of the MoTown cylinder block. That’s right; an alloy small-block. It carries all of the same strength-enhancing features of the iron version, plus more – like cross-valley ribs that not only strengthen the block, but also serve as cross-feed oilers for the lifters.
The promise, of course, of aluminum is lower mass and the alloy version of the MoTown weighs only 100 pounds in bare form. That’s more than 100 pounds less than the cast iron version. That’s a significant savings, no matter how you run the numbers – and it’s a saving that comes right off a car’s nose.
World Products doesn’t offer a 454-inch crate engine with the aluminum block, but you can order a 427-inch version. Think of it as a latter-day ZL1, with an advertised horsepower rating of 550 horsepower and 525 lb.-ft. of torque.