Chevrolet big-block engine
The Chevrolet Mark Engines colloquially referred to as the big block is a family of large-displacement, naturally-aspirated, 90°, overhead valve, gasoline-powered, V8 engines; that were developed and produced by the Chevrolet Division of General Motors, from the 1950s until present.
| Chevrolet big-block engine | |
|---|---|
454 big block in a 1970 Chevrolet Chevelle SS | |
| Overview | |
| Manufacturer | General Motors |
| Production | 1955–present |
| Layout | |
| Configuration | Naturally aspirated 90° V8 |
| Displacement | 348 cu in (5.7 L) 366 cu in (6.0 L) 396 cu in (6.5 L) 402 cu in (6.6 L) 409 cu in (6.7 L) 427 cu in (7.0 L) 454 cu in (7.4 L) 496 cu in (8.1 L) Aftermarket only: 502 cu in (8.2 L) 572 cu in (9.4 L) 622 cu in (10.2 L) 632 cu in (10.4 L) |
| Cylinder bore | 3.935 in (99.9 mm) 4.094 in (104.0 mm) 4+1⁄8 in (104.8 mm) 4+1⁄4 in (108.0 mm) 4.31 in (109.5 mm) 4.466 in (113.4 mm) 4.56 in (115.8 mm) 4.6 in (116.8 mm) |
| Piston stroke | 3+1⁄4 in (82.6 mm) 3+1⁄2 in (88.9 mm) 3.65 in (92.7 mm) 3.76 in (95.5 mm) 4 in (101.6 mm) 4.37 in (111.0 mm) 4+3⁄8 in (111.1 mm) 4+3⁄4 in (120.7 mm) |
| Cylinder block material | Cast iron |
| Cylinder head material | Cast iron, aluminum |
| Valvetrain | OHV 2 valves × cyl. |
| Compression ratio | 8.5:1, 9.0:1, 10.25:1, 11.0:1, 12.0:1, 12.5:1, 13.5:1 |
| Combustion | |
| Fuel system | Carburetor Fuel injection (Since Gen. V) |
| Fuel type | Gasoline |
| Cooling system | Water-cooled |
| Output | |
| Power output | 250–1,004 hp (186–749 kW) |
| Torque output | 385–876 lb⋅ft (522–1,188 N⋅m) |
| Dimensions | |
| Dry weight | 517–761 lb (235–345 kg) |
Chevrolet had introduced its popular small block V8 in 1955, but needed to create an engine with more displacement to power its medium duty trucks and the heavier cars that were on the drawing board. The first W-series big block, retroactively renamed Mark I, which debuted in 1958 at 348 cu in (5.7 L), was built in standard displacements up to 494 cu in (8.1 L), with aftermarket crate engines sold by Chevrolet exceeding 500 cu in (8.2 L). The last engine designation manufactured in this family are the Mark IV series.