3 Of The Biggest Chevy Crate Engines Ever Built

Chevrolet is known for producing a lineup of powerful small block Chevy crate engines. However, the biggest Chevy crate engines include big block varieties as well. Chevrolet's largest displacement and final, big block engine for production vehicles was the 496-cubic-inch 8.1L Vortec.

The 8100, as it's sometimes called, was the last big block engine derived from the same basic design that brought us Chevy engines such as the 6.5-liter 396, 7.0-liter 427, and 7.4-liter 454. Those engines, as some probably know, powered some of the most impressive Chevy muscle cars of all time, such as the Chevelle, Camaro, and Corvette, in addition to pickup trucks and other GM products.

According to Chevrolet, the company's performance group began producing crate engines in the late 1960s and has continued to improve its offerings to its customers. Big block Chevy crate engines include the familiar 427- and 454-cubic-inch varieties (some of the most powerful big block Chevy engines), but the biggest Chevy crate engines are those with displacement values like 502-, 572-, and 632-cubic-inches, easily taking the title of "Biggest Chevy Engine" from the once-mighty 8.1L Vortec.

At 632 cubic inches, the ZZ632 is the biggest big block crate engine available from Chevrolet. With its power ratings reported at 1,004 horsepower at 6,600 rpm and 876 lb-ft of torque 1,000 rpm sooner, the ZZ632/1000 Deluxe is clearly a powerful force. Especially when considering it accomplishes that power production using 93-octane pump gasoline.

The ZZ632/1000 Deluxe crate engine features electronic throttle body fuel injection; however, it's only intended for competition use. Other premium components found within the ZZ632/1000's tall-deck four-bolt main, cast-iron Bowtie engine block include forged aluminum alloy pistons, forged steel H-beam connecting rods, a forged 4340 steel crankshaft, and a billet steel hydraulic roller camshaft.

The 632 cubic inches come from the engine's 4.600-inch diameter cylinders and a 4.750-inch crankshaft stroke. ZZ632/1000 engine specs include camshaft durations of 270- and 287 degrees (intake and exhaust), 0.780-inch intake valve lift, and 0.782-inches for the exhaust valves. Intake valves measure 2.450 inches, and the exhaust valves are 1.800 inches in diameter. The titanium intake and exhaust valves, actuated by forged aluminum roller-style rocker arms, are housed in aluminum cylinder heads with 70cc combustion chambers. The nominal compression ratio is 12.0:1, and fuel is provided by 86-pound-per-hour injectors.

With 60 fewer cubic inches, the 572-cubic-inch big block Chevy crate engine features a cast-iron tall-deck engine block with four-bolt main caps securing a forged steel crankshaft. Its displacement derives from 4.560-inch diameter cylinders and 4.375-inches of stroke. Forged aluminum pistons attach to the crank via shot-peened forged steel connecting rods. The two ZZ572 varieties use rectangle-ported aluminum cylinder heads with differing part numbers, although Chevrolet lists similar specs for both. Both sets have 118cc combustion chambers, 2.250-inch intake, and 1.880-inch exhaust valve diameters and use the same rocker arms.

The ZZ572/620 Deluxe is the lower-rated of the two, delivering 621 horsepower at a modest 5,400 rpm and 645 lb-ft of torque at 4,200 rpm. While the ZZ572/620 isn't the most powerful 572-cubic-inch crate engine in Chevrolet's lineup, the ability to refuel at nearly any gas station makes it an attractive option for a hot rod. Of course, it's still only intended for competition use.

The ZZ572/720R Deluxe delivers 727 horsepower at 6,300 rpm and 680 lb-ft of torque at 4,900 rpm, making it one of Chevrolet's most powerful big blocks ever built. The gains are achieved thanks to its more aggressive mechanical roller cam, higher 12:1 compression ratio, a carburetor flowing an additional 300 CFM, and the 110-octane race gas required to fuel it.

Chevy's 502-cubic-inch crate engine is available as HT502, 502 HO, ZZ502/502, or SP502/605 options. As a result, the 502 big block offers a range of horsepower ratings. However, the 502 family has some common themes, such as cast-iron four-bolt main engine blocks, forged steel crankshafts and connecting rods, and forged aluminum pistons. In addition, they all have the same 4.470-inch diameter cylinders and 4.000-inch crankshaft stroke. The most powerful versions of the Chevy 502 crate engine feature more aggressive camshaft designs, compression ratios up to 10.0:1, and require premium pump gasoline.

Chevrolet bills its least powerful 502 crate engine, the HT502 available in long block form, as an alternative to rebuilding the big block in pre-1978 pickup trucks. With 406 horsepower at 4,200 rpm and 541 lb-ft of torque at 3,200 rpm, the HT502 represents a fine alternative to either the 8.1L Vortec or the venerable 454. The next rung on the 502 crate engine horsepower ladder is the 502 HO, shown online as a long block plus an intake manifold, with 461 horsepower at 5,100 rpm and 558 lb-ft of torque at 3,400 rpm.

The ZZ502/502 Deluxe delivers 508 horsepower at 5,200 rpm and 580 lb-ft of torque at 3,600 rpm. However, the most powerful 502 Chevy crate engine is the SP502/605 Deluxe with 605 horsepower at 6,000 rpm and 580 lb-ft of torque at 3,800 rpm.