See other engines in this family
BMW S63B44 specs: 4.4L (268 ci) 8-cylinder, 89 x 88.3 mm (3.5039 x 3.4764 in) bore and stroke, 9.3:1 compression. Rated 555 hp, 2010–2013. Used in the BMW X5.
The BMW S63B44 is close to square: 3.5039" bore against 3.4764" stroke, within 0.8%, which splits the difference between a high-revving layout and a torque layout. The 3.4764" stroke puts mean piston speed at 4,000 ft/min around 6,900 RPM, which is where a production bottom end is generally considered at its limit. Each of the 8 cylinders displaces 33.5 ci (549 cc).
9.3:1 is low by modern standards and generally happy on regular pump fuel.
It is one of 12 engines in the BMW 268ci family, all of them 268 ci — the differences between them are in compression, heads and rating, not displacement. 4 factory variants share these dimensions, rated at 555 hp across 2010–2013.
| Displacement | 268 ci / 4.4 L |
|---|---|
| Bore | 3.5039" |
| Stroke | 3.4764" |
| Cylinders | 8 |
| Configuration | V8 |
| Compression ratio | 9.3:1 |
| Bore/stroke ratio | 1.008 |
| Fuel type | gas |
|---|---|
| Advertised HP | 555 hp |
| Years | 2010–2013 |
| Year | Version | HP @ rpm | Torque @ rpm | Comp. |
|---|---|---|---|---|
| 2010 | S63B44 net | 555 @ 6000 | 500 lb-ft @ 1500 | 9.3:1 |
| 2011 | S63B44 net | 555 @ 6000 | 500 lb-ft @ 1500 | 9.3:1 |
| 2012 | S63B44 net | 555 @ 6000 | 500 lb-ft @ 1500 | 9.3:1 |
| 2013 | S63B44 net | 555 @ 6000 | 500 lb-ft @ 1500 | 9.3:1 |
Factory specification sheet.
| Bore/stroke character | 1.008 — square — bore and stroke are within 5%, a balanced compromise |
|---|---|
| Mean piston speed at 6,000 RPM | 3,476 ft/min — conservative for a street engine |
| Displacement per cylinder | 33.5 ci |
| Static compression | 9.3:1 — 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 |
|---|---|---|
| 2010 | 555 hp | S63B44 |
| 2011 | 555 hp | S63B44 |
| 2012 | 555 hp | S63B44 |
| 2013 | 555 hp | S63B44 |
1 factory vehicle, 2010–2013. Each year opens that model's engine table.