Chevrolet Reveals 1,004-HP Crate Engine, Its Most Powerful Ever

General Motors Recall
This April 26, 2017 file photo shows a Chevrolet sign at a Chevrolet dealership in Richmond, Va. General Motors more than 331,000 diesel pickup trucks in the U.S. for a second time in July 2021 because the engine block heater cords can short circuit and cause fires. The recall covers certain 2017 through 2019 Chevrolet Silverado and GMC Sierra 2500 and 3500 pickups with 6.6-liter diesel engines and block heaters. Steve Helber/AP Photo

Chevrolet today introduced the largest and most powerful crate engine in company history. The ZZ632/1000 naturally aspirated V8 engine produces 1004 horsepower and 876 pound-feet of torque.

"This is the biggest, baddest crate engine we've ever built," said Russ O'Blenes, director of the performance and racing propulsion team at General Motors. "The ZZ632 sits at the top of our unparalleled crate engine lineup as the king of performance. It delivers incredible power, and it does it on pump gas."

This 632-cubic-inch Big Block V8 reaches peak performance at 6,600 rpm and revs to a recommended maximum of 7,000 rpm.

The fuel is delivered by eight port injectors with the engine breathing through CNC-machined high-flow aluminum cylinder heads featuring symmetrical ports.

Traditionally, Big Blocks have been designed with variations in port shape from cylinder to cylinder; all eight intake ports of the ZZ632 have the same length, volume and layout. All of the ZZ632's exhaust ports are also identical. The symmetry is to ensure each individual cylinder will produce similar power.

The ZZ632's iron block shares a mold with Chevrolet Performance's ZZ572 crate engines, but the castings are machined to accommodate the 632-cubic-inch displacement.

ZZ632/1000 crate engine
The massive 632-cubic-inch Big Block V8 engine achieves peak performance at 6,600 rpm. General Motors

The bore grows by 0.040 inch compared to the 572-cubic-inch V8s, with most of the displacement gain coming from a stroke that's 0.375 inch longer. To provide clearance for that long stroke, engineers modified both the block and the connecting rods. Four-bolt main caps and a forged rotating assembly ensure strength and durability. During development, a single engine endured more than 200 simulated drag strip passes on a dynamometer.

The RS-X Symmetrical Port cylinder heads are designed and named for powertrain engineer Ron Sperry, who created them as one of his final accomplishments in more than 50 years working on General Motors performance and racing engines.

Sperry also introduced symmetrical ports to Chevy's Small Block V8 with the Gen III LS1 engine that debuted in the 1997 Chevrolet Corvette.

The ZZ632/1000 crate engine will be on display at the 2021 SEMA Show in Las Vegas, Nov. 2–5. Chevrolet Performance dealers will begin deliveries in early 2022.