Oldsmobile 231ci 9.8:1 Specs
Oldsmobile Oldsmobile 231ci · 3.800" × 3.400" · 9.8:1 engine specs: 231 ci (3.8L), 6-cylinder, 3.8" bore x 3.4" stroke, 9.8:1 compression.
Dimensions
| Displacement | 231 ci / 3.8 L |
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| Bore | 3.8" |
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| Stroke | 3.4" |
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| Cylinders | 6 |
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| Configuration | V6 |
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| Compression ratio | 9.8:1 |
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| Rod length | 5.96" |
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| Rod ratio | 1.753 |
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| Bore/stroke ratio | 1.118 |
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Construction
| Block material | cast iron |
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| Head material | cast iron |
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| Valvetrain | OHV |
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| Fuel type | gas |
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| Advertised HP | 165–205 hp |
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| Years | 1988–1993 |
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What these numbers mean
| Bore/stroke character | 1.118 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
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| Mean piston speed at 6,000 RPM | 3,400 ft/min — conservative for a street engine |
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| Rod ratio | 1.753 — long — less side loading on the cylinder wall, favours high RPM |
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| Displacement per cylinder | 38.5 ci |
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| Static compression | 9.8:1 — in the range that usually runs on pump premium |
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Cylinder head
| Intake valve diameter | 1.71" |
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| Exhaust valve diameter | 1.5" |
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Variants sharing these dimensions (5)
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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| 1988 | 165 hp | — |
| 1990 | 165 hp | — |
| 1991 | 165 hp | — |
| 1992 | 170 hp | — |
| 1993 | 205 hp | — |
Similar engines
← All Oldsmobile 231ci engines