GMC V8 engine
GMC shares engines with other General Motors divisions. But like their straight-6, GMC formerly had its own line of V8 engines.
| GMC V8 engine | |
|---|---|
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| Overview | |
| Manufacturer | General Motors |
| Production | 1955-2007 |
| Layout | |
| Configuration | 60° & 90° V8 |
| Displacement | 287–637 cu in (4.7–10.4 L) |
| Cylinder bore | 3.78 in (96 mm) 3.875 in (98.4 mm) |
| Piston stroke | 3.75 in (95.3 mm) |
| Block material | Cast-iron |
| Head material | Cast-iron |
| Valvetrain | OHV 2 valves x cyl. |
| Combustion | |
| Turbocharger | Duramax Diesel only |
| Fuel system | Carburetor, Fuel injection |
| Fuel type | Gasoline, Diesel |
| Cooling system | Water-cooled |
GMC engines
GMC's own V8 was the 637 cu in (10.4 L) 60 degree engine based on the big block 478 cu in (7.8 L) V6 (with two cylinders added). Bore was a massive 5.125” and stroke 3.86” for 637 cid. Power was listed as 275 HP @ 2800 rpm; torque 600 lbs ft @ 1600 rpm. Production started for 1966 and went through 1972.
Non-GMC engines
Pontiac
Prior to developing its own engines, smaller GMC's used the Pontiac V8 engine. They used the Pontiac 287-cubic-inch (4.7 L) engine for 1955 and 316-cubic-inch (5.2 L) engine in 1956, but advertised the engines as the "GMC 288" and "GMC 316". They used Pontiac's 347-cubic-inch (5.7 L) in 1957. For 1958, GMC reduced the bore of Pontiac's 370-cubic-inch (6.1 L) to 3.875 in (98.4 mm), resulting in a displacement of 336-cubic-inch (5.5 L). In Canada. For 1959, as the Pontiac engine's stroke was lengthened to 3.75 in (95.3 mm), a further bore reduction to 3.78 in (96.0 mm) was done to keep the displacement at approx. 336 cubic inches (5.5 L) (336.9).
Oldsmobile
Starting in 1955, for the larger trucks, the Oldsmobile Rocket V8 was available. In 1955 and 1956, it was 324 cubic inches (5.3 L). Power listed for 1956 was 210 HP @ 4200 rpm; torque was 305 lbs ft @ 2400 rpm. For the 1957 through 1959 model years, it was upped in bore and stroke and called the 370. Power listed as 232 HP @ 4200 rpm and torque as 355 lbs ft @ 2600 rpm. [1] Ref Motor’s Truck Repair Manuals various years.
Chevrolet Small-Block
From 1955 through 2003, GMC shared Chevrolet's small-block V8. This came in 265, 283, 305, 327, 350, and 400-cubic-inch (6.6 L) (4.3, 4.6, 5.3, 5.7, and 6.6 L) sizes.
Chevrolet Big-Block
GMC also shared Chevrolet's big-block V8 from 1968 through 2007 The company used the 366, 396, 402, 427, 454, 496, and 502 cubic inches (8.2 L) (6.0, 6.5, 6.6, 7.0,7.4, 8.1, and 8.2 L) versions.
GM Corporate Gen-III & Gen-IV V8 Engines
Beginning in 1999, GMC began offering GM's third-generation "small-block" V8 engine in various models. Through the years, engines have been offered in 4.8, 5.3 and 6.0-liter displacements. Most of the LS- or LT-based truck engines feature cast-iron cylinder blocks and heads for improved durability. [2]
Duramax engines
Beginning in 2001, GMC offered the same turbocharged Diesel Duramax V8 engines as were available in similar Chevrolet trucks. The engine family was co-developed by GM Powertrain and Isuzu, and has gone through numerous iterations through the years. Duramax engines are paired with a heavy-duty automatic transmission from GM's Allison division. [3]
See also
References
- A History of GMC Trucks, James K Wagner
- LS based GM small-block engine
- Duramax V8 engine