Bore, stroke, displacement and compression for all 14 Mazda Rotary engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 59.9–119.7 ci |
|---|---|
| Cylinders | 2, 3 |
| Bore | 3.543–4.134" |
| Stroke | 2.756–3.150" |
| Compression | 8.5–10.0:1 |
| Advertised power | 100–280 hp |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| 20B-REW | 119.7 ci | 4.1339" × 3.1496" | 9:1 | 280 |
| 13B-T | 80 ci | 4.1339" × 3.1496" | 8.5:1 | 185 |
| 13B MSP Renesis | 80 ci | 4.1339" × 3.1496" | 10:1 | 232 |
| 13B-T | 80 ci | 3.5433" × 3.1496" | 8.5:1 | 185 |
| 13B-REW | 80 ci | 3.5433" × 3.1496" | 9:1 | 255 |
| 13B-MSP (Renesis) | 80 ci | 3.5433" × 3.1496" | 10:1 | 232 |
| 13B | 79.8 ci | 3.5433" × 3.1496" | 9.4:1 | 135 |
| 13B-T (Series 5) | 79.8 ci | 4.1339" × 3.1496" | 9:1 | 200–255 |
| 13B-REW | 79.8 ci | 3.5433" × 3.1496" | 9:1 | 255 |
| 13B Rotary Turbo Series4 | 79.8 ci | 4.1339" × 3.1496" | 8.5:1 | 182 |
| Renesis 13B MSP | 79.8 ci | 4.1339" × 3.1496" | 10:1 | 232 |
| 12A | 70 ci | 3.5433" × 3.1496" | 9.4:1 | 100 |
| 12A Turbo | 70 ci | 4.1339" × 2.7559" | 8.5:1 | 160 |
| 10A | 59.9 ci | 3.5433" × 2.7559" | 9.4:1 | 100 |
Both bore and stroke vary across the family, so these are separate castings rather than variations on one block.
Compression spans 8.5:1 to 10:1, 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.