“Big Chevrolet engine !!!” said the press release in so many words. It’s strange, I thought; Chevy is kind of a button-down company, what the hell the hell the hell is going to blackmail them like that? Then I read the numbers. After I regained consciousness (I think I hit my head on the edge of the desk before I hit the floor) all I could mumble was, “Big Chevy Engine !!!”
Chevrolet Performance ZZ632 crank engine
There are two big numbers here. The first one is 632. That’s the displacement of this new V8 monster factory from The Bowtie Boys: 632 cubic inches. That’s over 10 liters. It’s big. But this is not the really large number. The very big number is 1004. This is the power output. During thousand! Add to that the 876 lb-ft. of torque, making the naturally aspirated ZZ632 / 1000 the largest and most powerful crate engine in Chevrolet history.
“It’s the biggest and worst crate engine we’ve ever built,” said Russ O’Blenes, general manager of the Performance and Racing Propulsion team. “The ZZ632 sits at the top of our unprecedented crate engine lineup as a performance king. It delivers incredible power, and it does it with gasoline at the pump.
Gas pump
Gas pump, I thought? What is he going to do on race gas? What is this thing gonna do about A V gas? And then my mind really started to run. How strong is the lower end? How much compression can it take? What size of blower can it take? What are the dimensions of the block, and can you fit it into a Gen 1 Nova? Then I calmed down and realized I had to finish writing this. I can call my drag racing friends later.
The Chevrolet Performance ZZ632 crate engine achieves maximum power at 6,600 rpm and maximum speed of 7,000 rpm. Torque peaks at around 5600 rpm, resulting in a reasonably tight but useful power range to work with. Then again, something tells me you’re not going to use the ZZ632 to shift gears on your favorite mountain road. Something tells me that the scenario will look more like “Green light!” Nail it! “
RS-X symmetrical port cylinder heads
Now check the details of the power supply and head design. Gas is supplied by eight port injectors with the engine breathing through CNC machined high flow aluminum cylinder heads featuring symmetrical ports. These RS-X symmetrical port heads are named after powertrain engineer Ron Sperry. Yes, this Ron Sperry. The guy who designed them for Chevrolet’s iconic Small Block V8 with the Gen III LS1 engine that debuted in the 1997 Corvette. And while the Big Blocks have traditionally been designed with variations in orifice shape. Cylinder to cylinder, the eight intake ports of the ZZ632 are the same length, volume, and layout.
Likewise, all the exhaust ports of the ZZ632 are identical. This symmetry ensures that the individual cylinders all produce similar power. It also ensures (if you think about the future) easier tuning when it comes to high volume racing power systems.
Cast iron beast
The ZZ632 block is cast iron which is a shame, in terms of weight, but I bet an alloy block would have collapsed 100 feet. The interesting thing about the ZZ632’s block architecture is that it shares a mold with the Chevrolet Performance ZZ572 crate engine. Chevy drilled the bore 0.040 inch from the 572, then they stroked it 0.375 inch.
To provide clearance for this long stroke, engineers modified both the block and the connecting rods. Four-bolt main caps and a forged rotating assembly provide strength and durability. During development, a single engine underwent over 200 simulated drag passes on a dynamometer.
In person and availability
The Chevrolet Performance ZZ632 crate engine will be on display at SEMA 2021 in Las Vegas, starting November 2. Chevrolet Performance dealers are expected to receive deliveries in early 2022, which means SEMA 2022 will be alight! In the meantime, check out the full specs table below. I have to calm down, then call a friend of mine in Woodburn.
Tony Borroz has spent his entire life driving vintage and sports cars. He is the author of Bricks & Bones: The Endearing Legacy and Nitty-Gritty Phenomenon of The Indy 500, available in paperback or Kindle formats. Follow his work on Twitter: @TonyBorroz.
Chevrolet Performance ZZ632 Crate Engine: Specification Table
| Chevrolet Performance ZZ632 / 1000 | |
| Shift | 632 cubic inches (10,348 cm3) |
| Bore x stroke | 4.60 x 4.75 inches |
| Compression ratio | 12.0: 1 |
| Power | 1,004 hp @ 6,600 rpm |
| Couple | 876 lb-ft @ 5,600 rpm |
| Maximum recommended engine speed | 7000 rpm |
| To block | Tall Deck 632 Bowtie Sportsman, Cast Iron, Four Bolt Main Caps |
| Cylinder heads | RS-X symmetrical port, CNC machined aluminum |
| Crankshaft | Wrought iron |
| Connecting rods | Wrought iron |
| Pistons | Forged aluminum |
| Fuel | Electronic port injection |
Photos and source: Chevrolet.
