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Hudson 308ci (1951–1952) specs: 308 ci 6-cylinder, 3.813 x 4.50 in (96.8 x 114.3 mm) bore and stroke, 7.2:1 compression. Rated 145 hp, 1951–1952.
The Hudson 308ci (1951–1952) is undersquare — the 4.5" stroke exceeds the 3.8125" bore by 15.3% — a layout that trades peak RPM for leverage and torque low in the range. With a 4.5" stroke, mean piston speed reaches 4,000 ft/min at only 5,350 RPM — the practical ceiling for a production bottom end — which is why a stroke this long makes its power low and runs out of safe revs early. Each of the 6 cylinders displaces 51.3 ci (841 cc).
7.2:1 is low by modern standards and generally happy on regular pump fuel.
2 factory variants share these dimensions, rated at 145 hp across 1951–1952.
| Displacement | 308 ci |
|---|---|
| Bore | 3.8125" |
| Stroke | 4.5" |
| Cylinders | 6 |
| Configuration | I6 |
| Compression ratio | 7.2:1 |
| Bore/stroke ratio | 0.847 |
| Fuel type | gas |
|---|---|
| Advertised HP | 145 hp |
| Years | 1951–1952 |
| Bore/stroke character | 0.847 — undersquare — stroke exceeds bore, which favours low-end torque |
|---|---|
| Mean piston speed at 6,000 RPM | 4,500 ft/min — in the range typical of performance street engines |
| Displacement per cylinder | 51.3 ci |
| Static compression | 7.2:1 — low by modern standards, generally happy on regular pump fuel |
Each link opens the calculator with this engine's specs already filled in.
These records share identical bore, stroke, displacement and compression. They differ by model year and factory power rating.
| Year | Advertised HP | Code |
|---|---|---|
| 1951 | 145 hp | — |
| 1952 | 145 hp | — |
1 factory vehicle, 1951–1952. Each year opens that model's engine table.