Ford 171ci specs: 3.661 x 2.70 in (93 x 68.6 mm) bore and stroke, shared by all 6 versions. Displacement, compression and factory ratings, plus rod ratio.
| Displacement | 171 ci |
|---|---|
| Cylinders | 6 |
| Bore | 3.661" |
| Stroke | 2.700" |
| Compression | 8.9–9.9:1 |
| Advertised power | 90–115 hp |
| Years | 1974–1985 |
| Cylinder head data | 4 of 6 engines |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| 1975 171 97HP | 171 ci | 3.661" × 2.7" | 9.872:1 | 97 |
| 1976 171 100HP | 171 ci | 3.661" × 2.7" | 9.862:1 | 100 |
| Ford 171ci · 3.661" × 2.700" · 8.952:1 | 171 ci | 3.661" × 2.7" | 8.952:1 | 90–93 |
| Ford 171ci · 3.661" × 2.700" · 8.852:1 | 171 ci | 3.661" × 2.7" | 8.852:1 | 100–109 |
| Z-code | 171 ci | 3.661" × 2.7" | — | 105 |
| Cologne V6, 2-bbl | 171 ci | 3.661" × 2.7" | — | 115 |
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.