Bore, stroke, displacement and compression for all 5 GMC Detroit Diesel V8 (Two-Stroke) engines, compared side by side. Free spec reference.
| Displacement | 318–736 ci |
|---|---|
| Cylinders | 6, 8 |
| Bore | 3.875–4.840" |
| Stroke | 4.500–5.000" |
| Compression | 17.0–18.7:1 |
| Advertised power | 185–450 hp |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| 8V92 | 736 ci | 4.84" × 5" | 17:1 | 450 |
| 8V71 | 568 ci | 4.25" × 5" | 18.7:1 | 318 |
| 6V71 | 426 ci | 4.25" × 5" | 18.7:1 | 230 |
| 8V53 | 424 ci | 3.875" × 4.5" | 17:1 | 250 |
| 6V53 | 318 ci | 3.875" × 4.5" | 17:1 | 185 |
Both bore and stroke vary across the family, so these are separate castings rather than variations on one block.
Compression spans 17:1 to 18.7:1, so fuel requirements differ meaningfully between members — worth checking before assuming parts interchange.
4 of 5 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.