| YF-1B | |
| Country Of Origin: | China |
| Date: | 1958-1969 |
| Designer: | Academy of Aerospace Liquid Propulsion Technology, Ren Xinmin, Mo Tso-hsin, Zhang Guitian |
| Associated: | DF-3A, DF-4 and Long March 1 |
| Predecessor: | С2.1100 |
| Successor: | YF-20 |
| Status: | Retired |
| Type: | liquid |
| Oxidiser: | N2O4 |
| Fuel: | UDMH |
| Cycle: | Gas Generator |
| Combustion Chamber: | 1 |
| Nozzle Ratio: | 10 |
| Thrust(Vac): | 303.6kN |
| Thrust(Sl): | 275.3kN |
| Chamber Pressure: | 7.1MPa |
| Burn Time: | 140s |
| Diameter: | 56cm (22inches) |
| Used In: | DF-3A, DF-4 and Long March 1 first stage. |
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.
The basic engine has been used since the DF-3 rocket and has been the main propulsion of the Long March 1 orbital launch vehicles.
While the basic engine was used multiple times, it was only used as a single engine for booster application. It is usually bundled into modules of multiple engines.
The relevant modules for first stage application are: