TorqueList Original Technical Art
Pontiac 317 V8
V8 · N/A
Pontiac · Traditional Pontiac V8
Pontiac 317 V8
Pontiac's 1956 displacement increase on the original Strato-Streak architecture.
316.6
Cubic inches
Pontiac enlarged its first-year 287 V8 to 316.6 cubic inches for 1956 and marketed it as the 317, including a rare 285-hp dual-quad performance version aimed at the horsepower race.
Displacement
316.6 ci
Bore
3.9375"
Stroke
3.25"
Years
1956
Key Takeaway
The 1956 Pontiac V8 enlarged bore to 3.9375 inches while retaining the original 3.25-inch stroke, increasing displacement to 316.6 cubic inches. Factory calibrations ranged from economy versions to a high-compression dual-quad performance package.
Technical Specifications
- Horsepower
- 192–285 hp gross depending factory combination
- Torque
- 297–359 lb-ft in common production versions; 330 lb-ft in the 285-hp dual-quad version
- Architecture
- 90-degree OHV V8
- Block
- Cast iron
- Cylinder heads
- Cast iron
- Valvetrain
- Pushrod OHV, 2 valves per cylinder
- Aspiration
- Naturally aspirated
- Fuel delivery
- Carbureted
- Main bearings
- 5
The 1956 Pontiac V8 enlarged bore to 3.9375 inches while retaining the original 3.25-inch stroke, increasing displacement to 316.6 cubic inches. Factory calibrations ranged from economy versions to a high-compression dual-quad performance package.
Internal Specifications
Variant-specific values are labeled. Engine families that span multiple years or RPOs can have different heads, cams, induction and rotating parts, so the exact code/year always takes priority.
Notable Applications
Strengths
- Early Pontiac V8 lineage
- Larger bore than the original 287
- Strong foundation for Pontiac's rapid displacement development
Weaknesses / Watch-outs
- Single-model-year displacement
- Restoration-oriented parts availability rather than broad performance support
Common Upgrades
- Period four-barrel induction
- Dual exhaust
- Ignition modernization hidden within stock appearance
Racing History & Legacy
The 316 was the second step in Pontiac's yearly displacement march from 287 to 389.
References & Image Credit
Engineering Notes Worth Knowing
316.6 cu in / 5.2 L with 3.9375 x 3.25-inch bore and stroke.
90-degree OHV Pontiac V8.
Factory versions ranged from 192 to 285 hp gross depending induction and compression.
The top dual-quad package used 10.0:1 compression and was rated at 285 hp.
History · context · related reading
The Story Behind Pontiac 317 V8
Pontiac wasted no time growing its new V8. Just one year after the 287, the division enlarged it again and even offered a dual-quad version aimed directly at the horsepower race.
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