If you want to keep that Turbine, then look into Blending the damage out Properly. Then get a re-balance done again, (this time hopefully more damage does not incur). The Stress Concentration areas will be prone to cracking from the heat cycles you put into the turbo.

This can be done safely: Just go easy and go light.

Edit: just saw your last post....Debris that hits the Wheel can also show on the turbine housing.

 

Well, from reading your response, I see that there isn't any other advice I can give that would help the situation. I still have my doubts on the electrolysis/carbon cleaning up those nicks, but oh well.
As for the electrolysis and the titanium alloy having issues, I doubt it. I use electrochemical etching all the time with titanium/Inconel/stainless, its a similar process and doesn't hurt the metal in any way. Even over a length of time in an electrolysis tank, the titanium should be perfectly fine, I wouldn't worry about that.

 

I'm sure OP knows this, but I'll throw it out there anyways. Be careful blending down to the depth of those nicks, they are deep enough that to get a nice smooth curve you would have to blend down at least half of the turbine "tip" so to speak.


This would cause a fairly large gap between the tip and turbine housing and a fairly big loss of efficiency. The smaller the gap between blade tip and housing, the more efficient the turbine/compressor. That's why a lot of Axial flow high pressure turbine blades are shrouded to improve efficiency.

 

thanks - good to hear some comments regarding the electrolysis process with relation to titanium alloys. I don;'t have any direct experience with that particular combination.

I appreciate all your responses. I've sent another message back to the tech, but from dealing with him throughout the past few months, i don't think i'll get any other meaningful response.

my concerns are based around my inexperience with titanium aluminide. If it was an inconel/steel turbine, i'd be much less worried.

 

Blending out the damage is an option, for the cost of doing that, then disassembling the unit, rebalancing and then reassemble to have compromised (airflow/blade profile), I could probably find another titanium turbine (even if I had to import one).

maybe I should pass on this particular item, sell it off, bite the bullet and use a 9.0t housing with an inconel turbine and sacrifice top end.

I was hoping that the titanium turbine would offset the boost threshold to allow me the same response but with a 10.5t housing.

Decisions decisions!!

 

SIGH
more issues, thinking of just sticking with the standard evo5 inconel turbo now.

I had a set of braided lines, water, oil etc for the new turbo.
the seller send the wrong size oil feed bolt to the turbo. m10x1.25 instead of m12x1.25. the slight difference meant it threaded fine, until it got to the bottom when I was torquing it down and it crossthreaded.

i found some small metal bits when backing the wrong bolt out, so im assuming there is some more metal debris inside the bearing housing.

now I'm left with a potentially contaminated bearing housing and a thread which i am not sure if I can feed the properly sized bolt back in.

any suggestions on how best to deal with this? new bearing housing altogether? or have the thread cleaned out, or have it rethreaded altogether to a bigger size and run new hardware altogether??

man this has turned out to be such a bigger mission than I thought
I'm trying to get in touch with the seller who sent me the braided equipment and hopefully they can help, but their terms and conditions spell out limited liability when it comes to installation and responsibility

 

I can't really help with the thread issue, since there's no good solution to that. But as for the possible metal shavings in the bearing area. I would suggest flushing them out with a liquid of some sort.


But make sure it's done flowing outward of where you messed up the threads, so start from the opposite and end push the contaminants away from the bearings if you know what I mean. Maybe blow some compressed air through there and then run a little oil through to grab ahold of the metal and then more compressed air to see what you can get out of it.

 

Thanks
Yeah, I managed to get in touch with the shop where I got the braided lines, they will send me the proper hardware. I will have to take the turbo off again and bring it into my usual workshop for them to retap the thread and make sure the new fittings will sit in properly.

I was concerned I'd have to go oversize, but looks like I can stick with a m12.

I will definitely get the housing flushed out .. when the m10 bolt torqued down, it pulled off the very tip of the threads, so there are little circular metal bits around. It will need to get flushed after the retap anyway

will keep you guys updated when I finally get everything in and tuned!