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BMW N63B44TU specs: 4.4L (268 ci) 8-cylinder, 89 x 88.3 mm (3.5039 x 3.4764 in) bore and stroke, 10:1 compression. Rated 445 hp, 2014–2016.
The BMW N63B44TU 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).
10:1 is in the range that usually runs on pump premium.
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. 3 factory variants share these dimensions, rated at 445 hp across 2014–2016.
| Displacement | 268 ci / 4.4 L |
|---|---|
| Bore | 3.5039" |
| Stroke | 3.4764" |
| Cylinders | 8 |
| Configuration | V8 |
| Compression ratio | 10:1 |
| Bore/stroke ratio | 1.008 |
| Fuel type | gas |
|---|---|
| Advertised HP | 445 hp |
| Years | 2014–2016 |
| Year | Version | HP @ rpm | Torque @ rpm | Comp. |
|---|---|---|---|---|
| 2014 | N63B44TU net | 445 @ 5500 | 480 lb-ft @ 2000 | 10:1 |
| 2015 | N63B44TU net | 445 @ 5500 | 480 lb-ft @ 2000 | 10:1 |
| 2016 | N63B44TU net | 445 @ 5500 | 480 lb-ft @ 2000 | 10:1 |
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 | 10:1 — in the range that usually runs on pump premium |
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 |
|---|---|---|
| 2014 | 445 hp | N63B44TU |
| 2015 | 445 hp | N63B44TU |
| 2016 | 445 hp | N63B44TU |
1 factory vehicle, 2014–2016. Each year opens that model's engine table.