Porsche 9A2EVO specs: 102 x 81.5 mm (4.0157 x 3.2087 in) bore and stroke, shared by all 2 versions. Displacement, compression and factory ratings.
| Displacement | 243.8–244 ci |
|---|---|
| Cylinders | 6 |
| Bore | 4.016" |
| Stroke | 3.209" |
| Compression | 13.3:1 |
| Advertised power | 502 hp |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| 40 MDG 992 GT3 | 244 ci | 4.0157" × 3.2087" | 13.3:1 | 502 |
| MDG.G | 243.8 ci | 4.0157" × 3.2087" | 13.3:1 | 502 |
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.