Hardcore Crate Engine Shootout

Big-block or small-block-pick your poison. This argument is as old as the hills and one that often crops up and divides the Car Craft staff. "Big-blocks make more power," claim the loyal big-inch contingent. "Small-blocks are much lighter than their big brothers; big-blocks make more torque, and more torque means more traction problems," counter the small-block loyalists. "But torque moves the car," say the big-block fans. All things being equal, a big-block will usually make more power and torque, but at what cost? The small-block usually gets the nod for lower cost, easier packaging, and good output per dollar. However, big-inch small-blocks are saddled with small-block-sized cylinder heads, and even marginal big-block heads will normally flow more air. You can't beat the appeal of a fat Rat nestled between your fenderwells, but whipping up on a big-block with a small-block means major bragging rights. And so it goes.

So, we decided to use our latest automotive acquisition as a testbed to revisit this oft-heated argument. We got our hands on two Bill Mitchell Hardcore Racing crate motors: a 427-inch small-block and a 509-inch big-block. The SuperNova's 383 was temporarily tossed aside and in its place went the 427-inch small-block crate motor to begin Phase One of our test. Phase Two was accomplished by shoehorning the 509-inch Rat into the poor SuperNova for more dragstrip thrashing. Will this issue be settled once and for all? You be the judge.

The Mouse That RoaredBill Mitchell Hardcore Racing's 427ci Mouse features pump-gas friendly compression, aluminum heads, and a svelte weight of only 435 pounds. Producing more than 540 hp and 523 lb-ft of torque (see "427 Dyno-Test" sidebar), this is a stout package indeed. Horsepower peaked at a low-stress (for a small-block) 6,000 rpm. The big-inch Mouse produced 1.24 horses per pound while the big-block was only able to muster 0.95 horses per pound. On paper, the Mouse looks better, but will torque tip the scales in the favor of the big-block? More important is the power-to-weight ratio when installed in the vehicle. The Mouse-equipped SuperNova features a power-to-weight ratio of 6.14 pounds per horsepower. With the 509 nestled between its fenders, SuperNova sported a superhero-like 5.76 pounds per horsepower.

What You'll NeedWhile they come fairly complete and already broken in on the dyno, there are still some items you will need before you can install and run your 427 or 509 crate motor.