In fact, throughout the life of the J-8, he has been worried about the engine.

The afterburner thrust of turbojet 7 is only 5.6 tons, two engines, and 11 tons of thrust, and the normal take-off weight of J-8 is 14 tons, if the aircraft is not designed into an elongated shape, it is impossible to reach a speed of more than Mach 2, this is still a normal take-off weight, the maximum take-off weight is 17 tons, the thrust-to-weight ratio is lower.

The turbojet-13 has not yet been successfully developed, and when the turbojet-13 comes out, the afterburner thrust is 6.6 tons, which is not bad compared to the turbojet-7, but it is still not enough.

Therefore, in history, when the turbojet-14 came out, the afterburner thrust was 7.5 tons, and the two were added together, which was 15 tons, and the deck had a thrust-to-weight ratio of more than 1 under the condition of normal take-off weight, and the appearance of this engine made the 601 overjoyed, in fact, the turbojet 14 was originally aimed at the J-7 and J-8 engine development, so the shape was completely suitable, and as a result, the J-8 couldn't wait to receive it and evolved into the J-8 3 fighter.

But what about the result?

The data of the turbojet 14 is good, but it is not qualified at all, and various technical problems continue to appear, and the plane began to crash during the test flight, and in order to let the J-8 have good performance, the 601 Institute is hard-headed, let the J-8 use the turbojet 14, and also equip the troops with a given nature.

The result?

The troops did not dare to use it at all, the J-8 of the army, the turbojet 14 engine was removed, and the turbojet 13 was replaced, even if the power was almost there, it could be used, in the research and development of the engine, there were too many lessons in China, and an unqualified engine, assembled to the aircraft, would bring very bad consequences, even if the research institute strongly promoted, the troops would also refuse.

The lesson in this regard, as well as J 10, after the domestic Taihang came out, he changed the J 10 with great interest, and the result? After flying a few times, it was resolutely replaced by Chengdu and could not be used!

Engine manufacturers must seriously do experimental modifications, immature, don't come to me, this is the biggest principle, technical problems must not be emotional, who is emotional, who is finished.

No matter how nice it sounds, the main engine factory must adhere to the principle and absolutely not let the problematic engine equip the troops.

After Taihang failed in the attempt to get from J 10, he began to match J 11, after all, J 11 is a double engine, but it still has been many years before it really matures, if J 10 gritted his teeth and used Taihang at that time, it would definitely be hated by the troops.

Now the J-8, there is only a turbojet-7 available, the Shenyang engine institute has begun the design of the turbojet-14, and plans to choose the 3-stage low-pressure compressor of the turbojet-13 engine and the blade shape of the first 7-stage high-pressure compressor of the reduced "Spey" engine. Based on the experience of engines such as turbofan 6 and turbojet 15, components such as combustion chambers, high and low pressure turbines, and afterburner combustion chambers were designed.

I don't know how many obstacles will be encountered in this kind of saved engine, and it is still unreliable to count on this kind of engine now.

Mr. Gu is now worried about the engine of the J-8.

Hearing Mr. Gu's words, Qin Feng also thought about it, that's right, the engine of this fighter is indeed a problem.

"Relying on our country, I'm afraid it will drag on for a long time." Qin Feng said: "If it can be imported from abroad, F404 and RB199 should be good." ”

Unlike in the past, now that the door to foreign countries has opened, since the whole machine can be introduced, it is also possible to introduce an engine.

Foreign high-thrust engines are not suitable, in terms of size, foreign medium thrust is more suitable, and now foreign advanced ones, can make the J-8 adopt, there are only these two.

F404 is the engine used by the American F-18 fighter, and it is also the world's best medium thrust, the size is appropriate, the fuel consumption rate is low, and the afterburner thrust is nearly 8 tons, two engines, the J-8 can simply carry out close combat air combat with the world's third-generation aircraft, and it can definitely meet the needs of energy maneuver theory.

The RB199, a European engine now fitted to the Tornado, is a unique three-rotor engine that represents the highest standard of European technology.

Moreover, judging from the current negotiations with foreign countries, the Americans only hope to sell the whole machine, do not want to sell parts, and do not like to sell technology, and the cooperation with the United Kingdom is relatively smooth, so the possibility of introducing RB199 is higher than the introduction of F404.

In fact, the goal of the J-8 is high-altitude and high-speed, under this index, the turbojet engine is the most suitable, and the turbofan engine is worse, but due to the high thrust-to-weight ratio and large thrust of this advanced turbofan engine, it is enough to make up for the shortcomings of the turbofan, and it is definitely the best choice for the J-8 to change the engine.

Qin Feng said his point of view.

"yes, we'd like to bring in one of those two as well." Mr. Gu said. Qin Feng knew, of course he also knew, after all, it was the forefront of aviation, and there were only a few.

It's a pity, although there are ready-made Spey engines in China, but they are not suitable, Spey engines are too thick, they can't be stuffed in, even if they expand the fuselage, stuffed in, Spey engines can't change the appearance of high-altitude weakness, the American F-4 ghosts, after being sold to the UK, Britain replaced the Spey engine, as a result, fuel saving is saved, but the high-altitude and high-speed performance is not good, acceleration and can't move.

The design idea of the J-8 is high-altitude and high-speed, and it can be intercepted quickly, so it is impossible to change the Spey for the J-8, and it can only be the introduction of a new engine.

"We are reporting to our superiors, hoping to go to investigate, if we can find a suitable engine and avionics from abroad, and replace our J-8, we can quickly improve its performance." Mr. Gu said: "It's just that I don't know how long it will take." ”

It is not easy to introduce from abroad, there will be long negotiations, look at Tu Lao's introduction of Marconi's avionics, and the hardships paid in the negotiations will be known.

I thought it was very simple in China, you put the price, I bought you a set to try, but foreign people refused to do it, people have to make a plan first, how many sets you want to buy, and then how the specific performance, all the things are negotiated, and finally the price can be negotiated. This introduction negotiation is exhausting.

"When we negotiate, you're going to come and help." Mr. Gu said: "Moreover, if it is really introduced, you can change it for J-8, or you can change it for J-7." ”

Knowing that this Qin Feng was not interested in 601, for fear that he would refuse, Mr. Gu said again.

Qin Feng nodded: "Yes, the world's aviation has begun to enter the era of turbofans, if we can introduce turbofan engines to our fighters, it will naturally be the best." ”

At this time, neither of them knew that J-8's hair change went through twists and turns, and finally ended up without a problem, and the plan to change J-7's hair went all the way down, and finally became a South Asian Thunder Dragon.