Bore, stroke, displacement and compression for all 13 Chevrolet Duramax engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 170–403 ci |
|---|---|
| Cylinders | 4, 6, 8 |
| Bore | 3.307–4.055" |
| Stroke | 3.543–4.134" |
| Compression | 15.0–17.5:1 |
| Advertised power | 181–470 hp |
| Years | 2001–2026 |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| Duramax · 4.055" × 3.898" · 17.5:1 | 403 ci | 4.0551" × 3.8976" | 17.5:1 | 300–310 |
| Duramax · 4.055" × 3.898" · 16.8:1 | 403 ci | 4.0551" × 3.8976" | 16.8:1 | 360–365 |
| Duramax · 4.055" × 3.898" · 16:1 | 403 ci | 4.0551" × 3.8976" | 16:1 | 397–445 |
| LB7 | 403 ci | 4.0551" × 3.8976" | — | 300 |
| LLY | 403 ci | 4.0551" × 3.8976" | — | 310 |
| LBZ | 403 ci | 4.0551" × 3.8976" | — | 360 |
| LMM | 403 ci | 4.0551" × 3.8976" | — | 365 |
| LML | 403 ci | 4.0551" × 3.8976" | — | 397 |
| L5P | 403 ci | 4.0551" × 3.8976" | — | 445–470 |
| Duramax · 3.307" × 3.543" · 15:1 | 183 ci | 3.3071" × 3.5433" | 15:1 | 277–305 |
| LM2 | 183 ci | 3.3071" × 3.5433" | — | 277 |
| LZ0 | 183 ci | 3.3071" × 3.5433" | — | 305 |
| LWQ | 170 ci | 3.622" × 4.1339" | 16.5:1 | 181 |
Both bore and stroke vary across the family, so these are separate castings rather than variations on one block.
Compression spans 15:1 to 17.5:1, so fuel requirements differ meaningfully between members — worth checking before assuming parts interchange.
4 of 13 are undersquare — stroke larger than bore, favouring torque low in the range.
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.