Are you being serious? This is the kind behavior that American policy makers do all the time. This is also why they constantly kick themselves in the balls and get face palmed when their "allies" have another option. China is known for their win-win approach to policy. It's why the international community trusts China's word. I'm talking about the real international community, not the American controlled one composed of American vassals. Russia and China need each other. Why aggravate them for short term gain? Besides this, look at Africa? Does China need Africa as badly as Russia? They don't and yet China is famous for providing them favorable trade, finance and diplomat policies.I think it will be a good idea to send a message to Russia that they have two choices; either sell China whatever engine technology it wants, or don't and China will catch up anyway through espionage/poaching/innovation/etc. Second choice might take longer, but end result is the same, which is that China will catch up to and surpass Russian engines. Russia can choose to cash out and speed up this process or not and watch its people starve. Not a hard decision to make I think.
The world isn't all Machiavellian lie-cheat-steal. That is the history of the Anglo-Americans and to a lesser extent of the West Europeans. There is a moral imperative that dictates what all Human Beings call "fair". This is the difference between China and many of the "developed" countries of today who base their national policies on winner take all thinking. This is also the main reason why the majority of the world's countries and population support China and Russia today despite the overwhelming global propaganda against them.