Porsche 928 specs: 95 x 78.9 mm (3.7402 x 3.1063 in) bore and stroke. Displacement, compression and factory ratings for each, plus rod ratio and piston speed.
| Displacement | 274.6 ci |
|---|---|
| Cylinders | 8 |
| Bore | 3.740" |
| Stroke | 3.106" |
| Compression | 8.5:1 |
| Advertised power | 240 hp |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| M28/01 | 274.6 ci | 3.7402" × 3.1063" | 8.5:1 | 240 |
This family is represented by a single engine in the database: 274.6 ci, 8 cylinders, a 3.7402" × 3.1063" 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.