Bore, stroke, displacement and compression for all 5 Oldsmobile Diesel engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 260–262 ci |
|---|---|
| Cylinders | 6, 8 |
| Bore | 3.700–4.057" |
| Stroke | 3.070–3.860" |
| Compression | 8.0–22.5:1 |
| Advertised power | 85–110 hp |
| Years | 1979 |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| LT6 | 262 ci | 4.057" × 3.385" | 21.6:1 | 85 |
| 262 V6 | 262 ci | 4.057" × 3.385" | 8:1 | 110 |
| LT6 | 262 ci | 3.8" × 3.86" | 21.6:1 | 85 |
| LF7 | 260 ci | 3.7" × 3.07" | 22.5:1 | 85 |
| LF7 | 260 ci | 3.7" × 3.07" | — | 90 |
Both bore and stroke vary across the family, so these are separate castings rather than variations on one block.
Compression spans 8:1 to 22.5:1, so fuel requirements differ meaningfully between members — worth checking before assuming parts interchange.
4 of 5 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.