Ford 312ci specs: 3.80 x 3.44 in (96.5 x 87.4 mm) bore and stroke, shared by all 5 versions. Displacement, compression and factory ratings, plus rod ratio.
| Displacement | 312 ci |
|---|---|
| Cylinders | 8 |
| Bore | 3.800" |
| Stroke | 3.440" |
| Compression | 8.4–9.7:1 |
| Advertised power | 215–300 hp |
| Years | 1956–1957 |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| 1956 312 215HP | 312 ci | 3.8" × 3.44" | 8.4:1 | 215 |
| 1956 312 225HP | 312 ci | 3.8" × 3.44" | 9:1 | 225 |
| Ford 312ci · 3.800" × 3.440" · 9.7:1 | 312 ci | 3.8" × 3.44" | 9.7:1 | 245–270 |
| 1957 312 300HP | 312 ci | 3.8" × 3.44" | — | 300 |
| E-code | 312 ci | 3.8" × 3.44" | — | 285 |
All are oversquare — bore larger than stroke, which favours revs over low-end torque.
Each engine page carries rod ratio, mean piston speed, bore/stroke character and cylinder head specs where published, and links into the calculators with its dimensions already filled in.