Bore, stroke, displacement and compression for all 15 Honda K-series engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 121.9–144 ci |
|---|---|
| Cylinders | 4 |
| Bore | 3.386–3.425" |
| Stroke | 3.386–3.898" |
| Compression | 8.8–11.5:1 |
| Advertised power | 150–315 hp |
| Years | 2002–2026 |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| K-series · 3.425" × 3.898" · 10.5:1 | 144 ci | 3.4252" × 3.8976" | 10.5:1 | 177–201 |
| K-series · 3.425" × 3.898" · 9.7:1 | 144 ci | 3.4252" × 3.8976" | 9.7:1 | 160–166 |
| K24W | 144 ci | 3.4252" × 3.8976" | 11.1:1 | 185 |
| K24W4 | 144 ci | 3.4252" × 3.8976" | 10:1 | 175 |
| K24Z7 | 144 ci | 3.4252" × 3.8976" | — | 201–205 |
| K23A1 | 140.3 ci | 3.3858" × 3.8976" | 8.8:1 | 240 |
| K20A (JDM Type R) | 121.9 ci | 3.3858" × 3.3858" | 11.5:1 | 217 |
| K-series · 3.386" × 3.386" · 11:1 | 121.9 ci | 3.3858" × 3.3858" | 11:1 | 197–210 |
| K-series · 3.386" × 3.386" · 9.8:1 | 121.9 ci | 3.3858" × 3.3858" | 9.8:1 | 160–306 |
| K20C2 | 121.9 ci | 3.3858" × 3.3858" | 10.8:1 | 158 |
| K20A3 | 121.9 ci | 3.3858" × 3.3858" | — | 160 |
| K20Z3 | 121.9 ci | 3.3858" × 3.3858" | — | 197 |
| K20C2 | 121.9 ci | 3.3858" × 3.3858" | — | 158 |
| K20C1 | 121.9 ci | 3.3858" × 3.3858" | — | 306–315 |
| K20C9 | 121.9 ci | 3.3858" × 3.3858" | — | 150 |
Both bore and stroke vary across the family, so these are separate castings rather than variations on one block.
Compression spans 8.8:1 to 11.5:1, so fuel requirements differ meaningfully between members — worth checking before assuming parts interchange.
6 of 15 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.