BMW 304ci specs: 84 x 75 mm (3.3071 x 2.9528 in) bore and stroke. Displacement, compression and factory ratings for each, plus rod ratio and piston speed.
| Displacement | 304 ci |
|---|---|
| Cylinders | 12 |
| Bore | 3.307" |
| Stroke | 2.953" |
| Compression | 8.8:1 |
| Advertised power | 296 hp |
| Years | 1988–1994 |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| M70B50 | 304 ci | 3.3071" × 2.9528" | 8.8:1 | 296 |
This family is represented by a single engine in the database: 304 ci, 12 cylinders, a 3.3071" × 2.9528" bore and stroke.
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.