Hi,
You are on the right track---. People need to understand---every successful system needs stability in its basic design and the engine. The fighter aircraft engine is as sacred as a heart is to a human body. You just don't go around changing the heart if it is working good.
For future aircraft----maybe with a slightly bigger frame and structure---a more powerful engine maybe needed to meet with more fuel---more electronics and more weapons carrying capabilities----.
So---for the BLK 2 for pakistan---RD93 is the engine. It is also the engine for the first order that has been procured.
Now as you mentioned about a higher numbers of JF17's sold---then as you stated---obviously---there will be other interesting parties that would want to participate.
Now come to think of it----the russian engine manufacturer is also not blind to what would happen---. It would be extremely ingorant of it to drop this contract to someone else by not providing the right engine for this aircaft---.
So---basically there is a battle for the engine between the chinese---the russians---the europeans----. The russians would really have to screw up or they would not have been able to come up with the upgraded power plant to lose this secured market.
As for the other poster who mentioned about twin engine aircraft---it has already been built and as
@Khafee pointed out---it is named as J31.
Now possibly for an upgraded version---the JF17 could be enhanced like the Grippen NG----or similar to the japanese F2---.
The only thing that is of most concern to me for the JF17 is the LOITER TIME of this aircraft----otherwise once it gets integrated with the PL15 and the PL12---the power projection of this aircraft would increase tremendoulsy---but still a heavy bird is of dire need.
