Bore, stroke, displacement and compression for all 10 Subaru EA engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 59.6–110 ci |
|---|---|
| Cylinders | 4 |
| Bore | 2.835–3.622" |
| Stroke | 2.362–2.638" |
| Compression | 7.7–9.5:1 |
| Advertised power | 36–115 hp |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| EA82 | 110 ci | 3.622" × 2.6378" | 9.5:1 | 90 |
| EA82T | 110 ci | 3.622" × 2.6378" | 7.7:1 | 115 |
| EA · 3.622" × 2.638" · 8.7:1 | 108.7 ci | 3.622" × 2.6378" | 8.7:1 | 72–73 |
| 82 NA | 108.7 ci | 3.622" × 2.6378" | 9.5:1 | 90 |
| EA · 3.622" × 2.638" · 7.7:1 | 108.7 ci | 3.622" × 2.6378" | 7.7:1 | 95–115 |
| EA · 3.622" × 2.362" · 9:1 | 97.3 ci | 3.622" × 2.3622" | 9:1 | 67–68 |
| EA-62 | 77.3 ci | 3.228" × 2.362" | 9:1 | 61 |
| EA-63 | 77.3 ci | 3.2283" × 2.3622" | 9:1 | 68 |
| 61 | 66.4 ci | 2.992" × 2.362" | 9:1 | 55 |
| EA-52 | 59.6 ci | 2.835" × 2.362" | 8:1 | 36 |
Both bore and stroke vary across the family, so these are separate castings rather than variations on one block.
Compression spans 7.7:1 to 9.5:1, so fuel requirements differ meaningfully between members — worth checking before assuming parts interchange.
All 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.