Bore, stroke, displacement and compression for all 4 Acura Honda H-series engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 132.7–139.6 ci |
|---|---|
| Cylinders | 4 |
| Bore | 3.425" |
| Stroke | 3.571–3.740" |
| Compression | 9.8–11.0:1 |
| Advertised power | 185–212 hp |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| H23A | 139.6 ci | 3.4252" × 3.7402" | 9.8:1 | 200 |
| H22A7 | 132.7 ci | 3.4252" × 3.5709" | 11:1 | 212 |
| Honda H-series · 3.425" × 3.571" · 10:1 | 132.7 ci | 3.4252" × 3.5709" | 10:1 | 185–200 |
| H22A | 132.7 ci | 3.4252" × 3.5709" | 10.6:1 | 190 |
Every engine here shares a 3.4252" bore; displacement varies by stroke alone, which is the signature of a family built on one block with different cranks.
1 of 4 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.