BMW 108ci specs: 89 x 71 mm (3.5039 x 2.7953 in) bore and stroke. Displacement, compression and factory ratings for each, plus rod ratio and piston speed.
| Displacement | 108 ci |
|---|---|
| Cylinders | 4 |
| Bore | 3.504" |
| Stroke | 2.795" |
| Compression | 8.8:1 |
| Advertised power | 101 hp |
| Years | 1980–1985 |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| M10B18 | 108 ci | 3.5039" × 2.7953" | 8.8:1 | 101 |
This family is represented by a single engine in the database: 108 ci, 4 cylinders, a 3.5039" × 2.7953" 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.