Bore, stroke, displacement and compression for all 6 GMC Ecotec I4 engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 83.2–145 ci |
|---|---|
| Cylinders | 4 |
| Bore | 2.854–3.465" |
| Stroke | 3.252–3.858" |
| Compression | 9.2–10.4:1 |
| Advertised power | 138–272 hp |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| Ecotec I4 · 3.465" × 3.858" · 10.4:1 | 145 ci | 3.4646" × 3.8583" | 10.4:1 | 177–180 |
| L850 | 134.2 ci | 3.3858" × 3.7244" | 10:1 | 145 |
| Ecotec I4 · 3.386" × 3.386" · 9.2:1 | 122 ci | 3.3858" × 3.3858" | 9.2:1 | 200–272 |
| LSJ | 122 ci | 3.3858" × 3.3858" | 9.5:1 | 205 |
| LKV | 90.8 ci | 2.9134" × 3.4094" | 10:1 | 163 |
| LUV | 83.2 ci | 2.8543" × 3.252" | 9.5:1 | 138 |
Both bore and stroke vary across the family, so these are separate castings rather than variations on one block.
4 of 6 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.