The 10.3-litre ZZ632/1000 is the most powerful crate engine Chevrolet has ever produced.
“BIGGER. BOLDER. BADDER.” So shouts the headline for Chevrolet’s latest crate engine.
While we’re mostly steeped in forward-thinking innovation and electrification these days, there’s still room in this column for the kind of technology that sets every petrolhead’s pulse racing.
A crate engine is an American phenomenon: simply an engine that you can buy and have delivered in a wooden crate for project use or as a replacement.
Chevy’s advert headline would be boastful if it wasn’t true to the point of understatement. Its new ZZ632/1000 engine is a big-block (as opposed to small-block) V8, which literally means it has a big cylinder block. It’s a term coined in the 1950s and generally implies more power but traditionally more weight and bulk as well. Chevy started the trend but was soon followed by Ford, and many great classic power units have since emerged from both companies.
There’s nothing subtle about this new Chevy V8, and the figures make for staggering reading. The ZZ632/1000 is so named because it has a capacity of 632 cubic inches (10,348cc) and, although naturally aspirated, produces 749kW at 6600rpm (plus 1188Nm of torque at 5600rpm). At a mere 3500rpm, the engine is producing a shade under 373kW and around 950Nm. It has a relatively high compression ratio yet is designed to run on only 93-octane fuel.
The pair of CNC-machined alloy cylinder heads are fitted with eight fuel injectors, one per cylinder, each capable of delivering up to 39kg of fuel per hour. At that rate, the engine would consume more than seven litres of fuel per minute.
Unusually for a big-block engine, all eight inlet ports are of the same length, volume and layout, and the exhaust ports are all identical too, the symmetry ensuring that each cylinder produces the same power. There are no overhead cams; the valves are operated by pushrods and rocker arms from a single camshaft in the block.
Despite being a long-stroke engine, with a bore and stroke of 116.84mm by 120.65mm, the V8 can rev to 7000rpm, compared with around 5500rpm for a big-block V8 back in the day.
The intake valves are of the dinner plate variety, measuring 60.96mm in diameter and made of titanium, as are the exhaust valves. The four-bearing crankshaft is immensely strong and manufactured from forged steel. The connecting rods are also of forged steel, while the pistons are made of forged aluminium.
The ZZ632/1000 is definitely tough. During durability testing, one example performed the equivalent of 200 drag-strip runs on a dynamometer.
Chevy makes the point that the engine is designed exclusively for use on track and its use on public roads might contravene American and Canadian emissions regulations. But for those with deep enough pockets, that doesn’t necessarily preclude its use in a road-legal car.
Introduced at November 2021’s SEMA show, this monster V8 is on sale now.
Jesse Crosse