Bore, stroke, displacement and compression for all 7 Ford IDI Diesel V8 engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 420.2–443.6 ci |
|---|---|
| Cylinders | 8 |
| Bore | 4.000–4.110" |
| Stroke | 4.180" |
| Compression | 21.5:1 |
| Advertised power | 170–190 hp |
| Years | 1983–1994 |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| 7 3 | 443.6 ci | 4.11" × 4.18" | 21.5:1 | — |
| 7.3L diesel | 443.6 ci | 4.11" × 4.18" | 21.5:1 | 180 |
| 7.3L IDI diesel | 443.6 ci | 4.11" × 4.18" | 21.5:1 | 185 |
| 7.3L IDI Turbo | 443.6 ci | 4.11" × 4.18" | 21.5:1 | 190 |
| 6 9 | 420.2 ci | 4" × 4.18" | — | — |
| IDI | 420.2 ci | 4" × 4.18" | 21.5:1 | — |
| 6.9L diesel | 420.2 ci | 4" × 4.18" | — | 170 |
Stroke is constant at 4.18" across the family — the displacement spread comes from bore, so these share a crank and differ in the block.
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.