Bore, stroke, displacement and compression for all 4 Subaru EZ engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 183–221.5 ci |
|---|---|
| Cylinders | 6 |
| Bore | 3.512–3.622" |
| Stroke | 3.150–3.583" |
| Compression | 10.5–10.7:1 |
| Advertised power | 212–256 hp |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| 36 Dohc | 221.5 ci | 3.622" × 3.5827" | 10.5:1 | 256 |
| EZ36D | 220 ci | 3.622" × 3.5827" | 10.5:1 | 256 |
| Ez30 | 183.1 ci | 3.5118" × 3.1496" | 10.7:1 | 212 |
| EZ · 3.512" × 3.150" · 10.7:1 | 183 ci | 3.5118" × 3.1496" | 10.7:1 | 212–245 |
Both bore and stroke vary across the family, so these are separate castings rather than variations on one block.
2 of 4 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.