Bore, stroke, displacement and compression for all 10 Mercury 385 engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 429–460 ci |
|---|---|
| Cylinders | 8 |
| Bore | 4.360" |
| Stroke | 3.590–3.850" |
| Compression | 8.0–10.5:1 |
| Advertised power | 197–370 hp |
| Years | 1969–1997 |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| 460 | 460 ci | 4.36" × 3.85" | 10.5:1 | 365 |
| 385 · 4.360" × 3.850" · 8:1 | 460 ci | 4.36" × 3.85" | 8:1 | 220 |
| 460 EFI | 460 ci | 4.36" × 3.85" | 8.5:1 | 245 |
| 7.5L EFI V-8 | 460 ci | 4.36" × 3.85" | — | 230–245 |
| 385 (1974–1976) | 460 ci | 4.36" × 3.85" | — | 202–220 |
| 385 460 | 460 ci | 4.36" × 3.85" | — | 197–218 |
| 429 | 429 ci | 4.36" × 3.59" | 10.5:1 | 320–360 |
| C-code / J-code | 429 ci | 4.36" × 3.59" | — | 370 |
| 429-2V | 429 ci | 4.36" × 3.59" | — | 320 |
| 429-4V | 429 ci | 4.36" × 3.59" | — | 360 |
Every engine here shares a 4.36" bore; displacement varies by stroke alone, which is the signature of a family built on one block with different cranks.
Compression spans 8:1 to 10.5:1, 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.