YF-1
| Country of origin | China | 
|---|---|
| Date | 1958-1969 | 
| Designer | Academy of Aerospace Liquid Propulsion Technology, Ren Xinmin, Mo Tso-hsin, Zhang Guitian | 
| Associated LV | DF-3A, DF-4 and Long March 1 | 
| Predecessor | С2.1100 | 
| Successor | YF-20 | 
| Status | Retired | 
| Liquid-fuel engine | |
| Propellant | N2O4 / UDMH | 
| Cycle | Gas Generator | 
| Configuration | |
| Chamber | 1 | 
| Nozzle ratio | 10 | 
| Performance | |
| Thrust, vacuum | 303.6 kN (68,300 lbf) | 
| Thrust, sea-level | 275.3 kN (61,900 lbf) | 
| Chamber pressure | 7.1 MPa (1,030 psi) | 
| Specific impulse, vacuum | 267.4 seconds (2.622 km/s) | 
| Specific impulse, sea-level | 242.5 seconds (2.378 km/s) | 
| Burn time | 140s | 
| Dimensions | |
| Diameter | 56 centimetres (22 in) | 
| Used in | |
| DF-3A, DF-4 and Long March 1 first stage. | |
| References | |
| References | |
The YF-1 was a Chinese liquid rocket engine burning N2O4 and UDMH in a gas generator cycle. It is a basic engine which when mounted in a four engine module forms the YF-2. It was used as the basis for developing a high altitude version known as the YF-3.
Some authors state that it was a direct copy of С.2.1100/С.2.1150 La-350 booster engine developed by Isayev OKB-2 (NII-88). What is known is that the engine development had great trouble with combustion instabilities and it took a long time to have a reliable combustion.