Pontiac 230ci specs: 3.875 x 3.25 in (98.4 x 82.6 mm) bore and stroke, shared by all 4 versions. Displacement, compression and factory ratings.
| Displacement | 230 ci |
|---|---|
| Cylinders | 6 |
| Bore | 3.875" |
| Stroke | 3.250" |
| Compression | 9.0–10.5:1 |
| Advertised power | 165–215 hp |
| Years | 1966–1967 |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| Pontiac 230ci (1967) · 215 hp | 230 ci | 3.875" × 3.25" | 10.501:1 | 215 |
| Pontiac 230ci · 3.875" × 3.25" · 9:1 | 230 ci | 3.875" × 3.25" | 9:1 | 165 |
| Pontiac 230ci · 3.875" × 3.25" · 10.5:1 | 230 ci | 3.875" × 3.25" | 10.5:1 | 207 |
| Pontiac 230ci · 3.875" × 3.25" · 10.501:1 | 230 ci | 3.875" × 3.25" | 10.501:1 | 215 |
Compression spans 9:1 to 10.501:1, so fuel requirements differ meaningfully between members — worth checking before assuming parts interchange.
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.