Porsche 911 specs: 90 x 70.4 mm (3.5433 x 2.7717 in) bore and stroke, shared by all 6 versions. Displacement, compression and factory ratings, plus rod ratio.
| Displacement | 163.9 ci |
|---|---|
| Cylinders | 6 |
| Bore | 3.543" |
| Stroke | 2.772" |
| Compression | 8.0:1 |
| Advertised power | 143–167 hp |
| Years | 1974–1977 |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| 911/92 | 163.9 ci | 3.5433" × 2.7717" | 8:1 | 150 |
| 911/92, 911/97 | 163.9 ci | 3.5433" × 2.7717" | — | 143 |
| 911/93, 911/98 | 163.9 ci | 3.5433" × 2.7717" | — | 167 |
| 911/43, 911/48, 911/44 | 163.9 ci | 3.5433" × 2.7717" | — | 157 |
| 911/82, 911/89, 911/84 | 163.9 ci | 3.5433" × 2.7717" | — | 157 |
| 911/85, 911/90 | 163.9 ci | 3.5433" × 2.7717" | — | 157 |
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.