Chevrolet has launched the largest ever displacement version of its COPO Camaro drag racecar. COPO stands for Central Office Production Order, indicating the acquisition of special versions of Chevrolet models. There have been COPO Camaros since 1969, initially as a means of evading GM’s then negative policy towards racing. The 2023 racecar will have a version of the V8 displacing 632 cu in - 10,357 cc - as has been available as the ZZ632 crate engine for a year or so.
Running on 93 octane pump fuel the ZZ632 develops 1004 bhp at 6600 rpm with 1188NM torque at 5600 rpm and its red line set at 7000 rpm. It was developed by the GM Performance and Racing Propulsion Team, which reportedly put an example through more than 200 simulated drag strip passes on an engine dyno.“This is the biggest, baddest crate engine we’ve ever built,” said Russ O’Blenes, director of the development team upon its launch.
The ZZ632 Big Block Chevrolet is port injected and uses specially developed CNC-machined aluminium heads. These are symmetrical meaning that all intake ports have the same layout, volume and length with that also true of the exhaust ports. This head is codenamed RS-X after GM powertrain engineer Ron Sperry. Sperry introduced symmetrical ports to the Chevrolet Small Block V8 with the Gen III LS1 engine first seen in the 1997 Corvette.
The ZZ632 was developed from well-established ZZ572 (9373 cc) crate motor including use of the same iron block casting, with appropriate machining differences. The bore is just 0.040 in (1.016 mm) larger while the stroke is 0.375 in (9.525 mm) longer.
The new COPO 632 V8 uses a slightly different camshaft to the ZZ632 crate engine, although both versions exploit valve lift of 0.780 in intake and 0.782 in exhaust. The two engines have different water pumps, the crate motor using a mechanical pump, the COPO a Meziere electric pump. In all other respects both versions of the 632 would appear to be identical.
The ZZ572 powered the COPO Camaro that won the 2022 NHRA Factory Stock Showdown. At the time of writing it was not confirmed that the new larger displacement racecar will be eligible for that contest but all of the 632 racecars had been pre-sold.