Bore, stroke, displacement and compression for all 4 Toyota FA (Subaru-built) engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 122–145.7 ci |
|---|---|
| Cylinders | 4 |
| Bore | 3.386–3.701" |
| Stroke | 3.386" |
| Compression | 12.5:1 |
| Advertised power | 200–228 hp |
| Years | 2013–2026 |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| FA24 | 145.7 ci | 3.7008" × 3.3858" | 12.5:1 | — |
| FA24 | 145.7 ci | 3.7008" × 3.3858" | 12.5:1 | 228 |
| FA20 | 122 ci | 3.3858" × 3.3858" | 12.5:1 | — |
| FA20 | 122 ci | 3.3858" × 3.3858" | 12.5:1 | 200–205 |
Stroke is constant at 3.3858" across the family — the displacement spread comes from bore, so these share a crank and differ in the 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.