I am again guessing that Kaveri may be around the developmental stage of early jet engines. Frank Whittle type stuff maybe? The Russians bypassed such issues by making them cheap and changing engines soon, I think. I mean it is technically OK to have an engine that works for only 10 hours as long as you have a replacement line with 3 spare engines to use while each used up engine is taken apart for replacing blades etc
The present stage of Kaveri is somewhere at J79 (the Phantom F4 engines) and F100 (the F16A/B engines) .. ie late 70s US engines.
There is no secret here. The material technology you have determines what sort of engine you can have. The key here is engine thrust to weight. If you want the GE414/ EJ200/M88 class, you need that class of materials and technology. The list for that would be, blisks (integrally bladed disks), single crystal turbine blades , and thermal barrier coatings (that is electron beam vapor deposited).
And without the engine of the thrust to weight class, you cannot have a competitive fighter! So, unless you tell the IAF to accept fighters that are less than state of art (good luck, given the record of the LCA and Arjun with the armed forces), that wont happen (the Chinese do on the other hand, their J20 stealth ding dong will suck hard and their nuke boats suck harder.. but hey they do field it).
In any case, this is and R&D failure on the materials side. This is what I told Mullah Enqyoobuddin when we were having that discussion. This failure is really not GTRE's , but DMRL's. This kind of material break throughs are their responsibility and stuff like electron beam deposition , powder metallurgy, friction welding and processes are what they should and do pour R&D money into. It really is the silence of the DMRL lambs.
Design wise, I do think the GTRE has delivered against all odds. With the right materials,the engine will be up to scratch thrust wise and MBTF wise (in fact whatever KN ahchieved would be the restricted thrust with available materials, the engine has to stand up during testing anyways). The plan would have been always to get the design right and then the materials. Well, no one thought GTRE would succeed , but hey they actually did and have a working engine, and now when the time has come to put the required materials in, the DMRL has turned out as 'Nood" and hence the turn to the French.
In fact, given the changes in India, it is good. We should integrate with the global supply chain and tap in to the R&D and material base where need across the world. This 100% indigenous fetish is garbage, was always garbage and should be given up for good. If the DMRL guys can come up with competitive materials in time for the next engine, good, consider it, otherwise, get it from abroad.
This Chinese like strategy of fielding lame duck stuff cant work in the Indian context, where we actually have to fight wars and we dont have China's luxury of not having to fight wars and try "fleet in being" tactics. Our wars are actual shooting wars not hiss and scare kind of things.