The General may be investing in a greener future, what with its announcement to shift its entire automobile fleet to electric by 2035, but thankfully for us gearheads, today is not that day.
Chevrolet Performance today introduced the all-new ZZ632/1000 crate engine — the largest and most powerful crate engine in the brand’s history. The naturally-aspirated 632-cubic-inch V-8 produces 1,004 horsepower and 876 lb-ft of torque, and is intended for offroad competition use.
“This is the biggest, baddest crate engine we’ve ever built,” said Russ O’Blenes, GM director of the Performance and Racing Propulsion Team. “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.”
The big block V-8 reaches peak power at 6,600 rpm and revs to a recommended maximum of 7,000 rpm. Fuel is delivered by eight port injectors with the engine breathing through CNC-machined high-flow aluminum cylinder heads with symmetrical ports. While big-blocks have traditionally 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. Similarly, all of the ZZ632’s exhaust ports are identical, and this symmetry ensures individual cylinders all produce similar power.
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. – Russ O’Blenes, GM
The RS-X Symmetrical Port cylinder heads are named for powertrain engineer Ron Sperry, who designed them as one of his final accomplishments in his 50 years working on General Motors performance and racing engines. Sperry also introduced symmetrical ports to Chevy’s iconic small-block V-8 with the Gen III LS1 engine that debuted in the 1997 Chevrolet Corvette.
The ZZ632’s iron block shares a mold with Chevrolet Performance’s ZZ572 crate engines, but the castings are machined to accommodate the massive 632-cubic-inch displacement. The bore grows by 0.040-inch compared to the 572-cubic-inch V-8s, 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.
In September, Chevrolet quietly discontinued its 6.2-liter, 755 horsepower LT5 crate engine, paving the way for this new behemoth. The ZZ632 goes head-to-head with Mopar’s 1,000 horsepower, 7.0-liter “Hellephant” HEMI crate engine.
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.
Chevrolet Performance ZZ632/1000
Displacement: 632 cu in (10,348 cc)
Bore x Stroke: 4.60 x 4.75 in
Compression Ratio: 12.0:1
Power: 1,004 hp @ 6600 rpm
Torque: 876 lb-ft @ 5600 rpm
Maximum Recommended Engine Speed: 7,000 rpm
Block: Tall Deck 632 Bowtie Sportsman, cast iron, four-bolt main caps
Cylinder Heads: RS-X Symmetrical Port, CNC-machined aluminum
Crankshaft: Forged steel
Connecting Rods: Forged steel
Pistons: Forged aluminum
Fuel: Electronic port injection