Subaru ER specs: 92 x 67 mm (3.6220 x 2.6378 in) bore and stroke. Displacement, compression and factory ratings for each, plus rod ratio and piston speed.
| Displacement | 163.1 ci |
|---|---|
| Cylinders | 6 |
| Bore | 3.622" |
| Stroke | 2.638" |
| Compression | 9.5:1 |
| Advertised power | 145 hp |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| ER27 | 163.1 ci | 3.622" × 2.6378" | 9.5:1 | 145 |
This family is represented by a single engine in the database: 163.1 ci, 6 cylinders, a 3.622" × 2.6378" bore and stroke.
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.