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The same engine also has a main page: Oldsmobile 260.
Oldsmobile 260 specs: 260 ci (4.3L) 8-cylinder, 3.70 x 3.06 in (94 x 77.7 mm) bore and stroke, 8:1 compression. Rated 110 hp. OHV. Rod ratio and piston speed.
The Oldsmobile Small-Block V8 (260) is oversquare — the 3.7" bore exceeds the 3.0598" stroke by 20.9% — a layout that favors airflow and RPM over leverage at the crank. The 3.0598" stroke does not reach 4,000 ft/min of mean piston speed until about 7,850 RPM, so piston speed is not what limits this engine's revs — valvetrain and breathing are. Each of the 8 cylinders displaces 32.5 ci (533 cc).
8:1 on iron heads is low by modern standards and generally happy on regular pump fuel.
Factory fitments include the Oldsmobile Cutlass, Oldsmobile Omega, Oldsmobile Starfire.
| Displacement | 260 ci / 4.3 L |
|---|---|
| Bore | 3.7" |
| Stroke | 3.0598" |
| Cylinders | 8 |
| Compression ratio | 8:1 |
| Bore/stroke ratio | 1.209 |
| Block material | cast iron |
|---|---|
| Head material | cast iron |
| Valvetrain | OHV |
| Fuel type | gas |
| Advertised HP | 110 hp |
| Bore/stroke character | 1.209 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
|---|---|
| Mean piston speed at 6,000 RPM | 3,060 ft/min — conservative for a street engine |
| Displacement per cylinder | 32.5 ci |
| Static compression | 8:1 — low by modern standards, generally happy on regular pump fuel |
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