See other engines in this family
BMW S50B30US specs: 3.0L (182.7 ci) 6-cylinder, 86 x 85.8 mm (3.3858 x 3.3780 in) bore and stroke, 10.5:1 compression. Rated 240 hp, 1995.
The BMW S50B30US is close to square: 3.3858" bore against 3.378" stroke, within 0.2%, which splits the difference between a high-revving layout and a torque layout. The 3.378" stroke does not reach 4,000 ft/min of mean piston speed until about 7,100 RPM, so piston speed is not what limits this engine's revs — valvetrain and breathing are. Each of the 6 cylinders displaces 30.5 ci (499 cc).
10.5:1 on aluminum heads is in the range that usually runs on pump premium; aluminum sheds heat faster than iron, which makes the same number a little more forgiving.
It is one of 7 engines in the S5x family, the smallest at 182.7 ci.
| Displacement | 182.7 ci / 3 L |
|---|---|
| Bore | 3.3858" |
| Stroke | 3.378" |
| Cylinders | 6 |
| Configuration | I6 |
| Compression ratio | 10.5:1 |
| Bore/stroke ratio | 1.002 |
| Block material | cast iron |
|---|---|
| Head material | aluminum |
| Valvetrain | DOHC |
| Fuel type | gas |
| Firing order | 1-5-3-6-2-4 |
| Advertised HP | 240 hp |
| Years | 1995 |
| Year | Version | HP @ rpm | Torque @ rpm | Comp. |
|---|---|---|---|---|
| 1995 | S50B30US net | 240 @ 6000 | 225 lb-ft @ 4250 | 10.5:1 |
Factory specification sheet.
| Bore/stroke character | 1.002 — square — bore and stroke are within 5%, a balanced compromise |
|---|---|
| Mean piston speed at 6,000 RPM | 3,378 ft/min — conservative for a street engine |
| Displacement per cylinder | 30.4 ci |
| Static compression | 10.5:1 — in the range that usually runs on pump premium |
Each link opens the calculator with this engine's specs already filled in.
1 factory vehicle, 1995. Each year opens that model's engine table.