Bore, stroke, displacement and compression for all 3 Chevrolet 145ci engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 145 ci |
|---|---|
| Cylinders | 4, 6 |
| Bore | 3.438–3.465" |
| Stroke | 2.600–3.858" |
| Compression | 8.0–10.4:1 |
| Advertised power | 80–171 hp |
| Years | 1960–2006 |
| Cylinder head data | 2 of 3 engines |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| Chevrolet 145ci (2006) · 171 hp | 145 ci | 3.465" × 3.858" | 10.4:1 | 171 |
| Chevrolet 145ci · 3.438" × 2.6" · 8:1 | 145 ci | 3.438" × 2.6" | 8:1 | 80 |
| Chevrolet 145ci · 3.438" × 2.6" · 8.25:1 | 145 ci | 3.438" × 2.6" | 8.25:1 | 150 |
Both bore and stroke vary across the family, so these are separate castings rather than variations on one block.
Compression spans 8:1 to 10.4:1, so fuel requirements differ meaningfully between members — worth checking before assuming parts interchange.
The family mixes oversquare and undersquare designs, so members behave quite differently despite sharing a name.
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.