American Motors 343ci 10.2:1 Specs
American Motors American Motors 343ci · 4.08" × 3.28" · 10.2:1 engine specs: 343 ci (5.6L), 8-cylinder, 4.08" bore x 3.28" stroke, 10.2:1 compression.
Dimensions
| Displacement | 343 ci / 5.6 L |
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| Bore | 4.08" |
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| Stroke | 3.28" |
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| Cylinders | 8 |
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| Compression ratio | 10.2:1 |
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| Rod length | 5.875" |
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| Rod ratio | 1.791 |
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| Bore/stroke ratio | 1.244 |
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| Piston deck clearance | 0.05" |
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Construction
| Induction | 1-4 |
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| Advertised HP | 280 hp |
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| Years | 1967–1969 |
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What these numbers mean
| Bore/stroke character | 1.244 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
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| Mean piston speed at 6,000 RPM | 3,280 ft/min — conservative for a street engine |
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| Rod ratio | 1.791 — long — less side loading on the cylinder wall, favours high RPM |
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| Displacement per cylinder | 42.9 ci |
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| Static compression | 10.2:1 — in the range that usually runs on pump premium |
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Cylinder head
| Intake valve diameter | 2.025" |
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| Exhaust valve diameter | 1.625" |
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| Chamber volume | 51.39 cc |
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| Rocker ratio | 1.6:1 |
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| Lifter type | hydraulic |
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Variants sharing these dimensions (3)
These records share identical bore, stroke, displacement and compression. They differ by model year and factory power rating.
| Year | Advertised HP | Code |
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| 1967 | 280 hp | — |
| 1968 | 280 hp | — |
| 1969 | 280 hp | — |
Similar engines
Source: NHRA blueprints — nhra.net blueprints
← All American Motors 343ci engines