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Buick 248ci (1937–1950) specs: 248 ci 8-cylinder, 3.094 x 4.125 in (78.6 x 104.8 mm) bore and stroke. Rated 107-125 hp, 1937–1950. Used in the Buick Special.
The Buick 248ci (1937–1950) is undersquare — the 4.125" stroke exceeds the 3.0938" bore by 25.0% — a layout that trades peak RPM for leverage and torque low in the range. The 4.125" stroke puts mean piston speed at 4,000 ft/min around 5,800 RPM, which is where a production bottom end is generally considered at its limit. Each of the 8 cylinders displaces 31.0 ci (508 cc).
11 factory variants share these dimensions, rated from 107 to 125 hp across 1937–1950.
| Displacement | 248 ci |
|---|---|
| Bore | 3.0938" |
| Stroke | 4.125" |
| Cylinders | 8 |
| Configuration | V8 |
| Compression ratio | 6.1–6.6:1 (published figures vary) |
| Bore/stroke ratio | 0.75 |
| Fuel type | gas |
|---|---|
| Advertised HP | 107–125 hp |
| Years | 1937–1950 |
| Year | Version | HP @ rpm | Torque @ rpm | Comp. | Duration int / exh | Valve lift int / exh | LSA |
|---|---|---|---|---|---|---|---|
| 1938 | gross | 107 | — | — | — | — | — |
| 1939 | gross | 107 @ 3400 | 203 lb-ft @ 2000 | 6.1:1 | — | — | — |
| 1940 | gross | 107 @ 3400 | 203 lb-ft @ 2000 | 6.1:1 | 261° / 257° | — | 112° |
| 1941 | gross | 115 | — | — | — | — | — |
| 1941 | gross | 125 | — | — | — | — | — |
| 1948 | gross | 110 @ 3600 | 206 lb-ft @ 2000 | 6.3:1 | 261° / 257° | — | 112° |
| 1950 | gross | 115 @ 3600 | 212 lb-ft @ 2000 | 6.6:1 | 261° / 257° | — | 112° |
Factory specification sheet. Durations are the factory's advertised figures at the basis printed on the sheet, not duration at .050" lift; lobe separation is calculated from the printed valve timing.
| Bore/stroke character | 0.750 — undersquare — stroke exceeds bore, which favours low-end torque |
|---|---|
| Mean piston speed at 6,000 RPM | 4,125 ft/min — in the range typical of performance street engines |
| Displacement per cylinder | 31.0 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 |
|---|---|---|
| 1937 | — | — |
| 1938 | 107 hp | — |
| 1939 | 107 hp | — |
| 1940 | 107 hp | — |
| 1941 | 115 hp | — |
| 1941 | 125 hp | — |
| 1942 | — | — |
| 1946 | — | — |
| 1947 | 110 hp | — |
| 1948 | 110 hp | — |
| 1950 | 115 hp | — |
1 factory vehicle, 1937–1950. Each year opens that model's engine table.