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Studebaker 185ci (1955–1958) specs: 185 ci 6-cylinder, 3.00 x 4.375 in (76.2 x 111.1 mm) bore and stroke. Rated 92-101 hp, 1955–1958.
The Studebaker 185ci (1955–1958) is undersquare — the 4.375" stroke exceeds the 3" bore by 31.4% — a layout that trades peak RPM for leverage and torque low in the range. With a 4.375" stroke, mean piston speed reaches 4,000 ft/min at only 5,500 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 30.8 ci (505 cc).
7 factory variants share these dimensions, rated from 92 to 101 hp across 1955–1958.
| Displacement | 185 ci |
|---|---|
| Bore | 3" |
| Stroke | 4.375" |
| Cylinders | 6 |
| Configuration | I6 |
| Compression ratio | 7.5–7.8:1 (published figures vary) |
| Bore/stroke ratio | 0.686 |
| Fuel type | gas |
|---|---|
| Advertised HP | 92–101 hp |
| Years | 1955–1958 |
| Bore/stroke character | 0.686 — undersquare — stroke exceeds bore, which favours low-end torque |
|---|---|
| Mean piston speed at 6,000 RPM | 4,375 ft/min — in the range typical of performance street engines |
| Displacement per cylinder | 30.8 ci |
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 |
|---|---|---|
| 1955 | 92 hp | — |
| 1955 | 101 hp | — |
| 1956 | — | — |
| 1956 | 101 hp | — |
| 1957 | 92 hp | — |
| 1957 | 101 hp | — |
| 1958 | 101 hp | — |
3 factory vehicles, 1955–1958. Each year opens that model's engine table.