An engine designed and manufactured by Hirth Motoren GmbH. It was used in the Heinkel He 71, Klemm Kl 35, and Bücker Bü 131 Jungmann aircraft.
| Configuration | 4-cylinder inverted inline |
| Cooling | air |
| Compression ratio | 5.8 |
| Displacement | 3.6 l |
| Weight | 84 kg |
| Maximum power | 80 hp at 2,400 rpm |
| Rated power | 65 hp at 2,000 rpm |
