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BMW M10 specs: 1.6L (96 ci) 4-cylinder, 84 x 71 mm (3.3071 x 2.7953 in) bore and stroke, 8.6:1 compression. Rated 85 hp, 1968–1971. Used in the BMW 2002.
The BMW 96ci (M10) is oversquare — the 3.3071" bore exceeds the 2.7953" stroke by 18.3% — a layout that favors airflow and RPM over leverage at the crank. The 2.7953" stroke does not reach 4,000 ft/min of mean piston speed until about 8,600 RPM, so piston speed is not what limits this engine's revs — valvetrain and breathing are. Each of the 4 cylinders displaces 24.0 ci (393 cc).
8.6:1 is low by modern standards and generally happy on regular pump fuel.
4 factory variants share these dimensions, rated at 85 hp across 1968–1971.
| Displacement | 96 ci / 1.6 L |
|---|---|
| Bore | 3.3071" |
| Stroke | 2.7953" |
| Cylinders | 4 |
| Configuration | I4 |
| Compression ratio | 8.6:1 * |
| Bore/stroke ratio | 1.183 |
* Compression ratio from a single source; not yet cross-verified.
| Fuel type | gas |
|---|---|
| Advertised HP | 85 hp |
| Years | 1968–1971 |
| Bore/stroke character | 1.183 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
|---|---|
| Mean piston speed at 6,000 RPM | 2,795 ft/min — conservative for a street engine |
| Displacement per cylinder | 24.0 ci |
| Static compression | 8.6:1 — low by modern standards, generally happy on regular pump fuel |
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 |
|---|---|---|
| 1968 | 85 hp | M10 |
| 1969 | 85 hp | M10 |
| 1970 | 85 hp | M10 |
| 1971 | 85 hp | M10 |
1 factory vehicle, 1968–1971. Each year opens that model's engine table.