VTECth1s

I just bought a used Holset big H1C, with the 54-ind./83-exd. compressor wheel. Has probably 10K+ miles. I've checked for shaft play. And it has very minimal to nearly zero in/out or side to side play, it's real solid, tight and spins smoothly. Got home and wanted to do some further inspection. Got both the compressor housing and turbine housing off.

But before taking out the comp. housing, I spun the wheel at least 10 different times. And it spins smoothly, I spun it from the comp nut, and from the fins too. And it glides and spins pretty smoothly/freely, I don't hear or see the comp wheel touching or hitting the comp. wall. Then I removed the housing, I took a look at the compressor wheel. There's no chipped fins, but a slight bend on the very tip of 1 or 2 fins, and a hair line crack on the tip of one fin about 1.5-2mm in length, very minute crack. The sides of the fins and wheel look smooth. The turbine wheel is clean no cracks, chips, bends or any imperfections that I can see. Very minimal to no play on it either. There's also minimal carbon build up on the turbine side. Both wheels look substantially clean, no oil residue or leaks either.

Anyway, I did notice when I inspected the comp. housing. There was some light scratches on the backside of the housing, doesn't look like a circular pattern though. Also some light scratching along the wall where the inducer is exposed.

Can the compressor housing me machined to smooth out those scratches?
I already plan to replace the comp. wheel and get a rebuild kit for peace of mind. And doing the work myself.

I've read or heard that if the comp. wheel makes even slight contact with the comp housing, it's considered unrepairable or rebuild-able? Honestly there is almost no shaft play when I spin the turbine and/or compressor wheel. It's looks and feels like a pretty good used turbo.

What do you guys think about the comp. housing needing some machine work to smooth out the scratches? I'll post up pictures when I get home to get a better idea of what I'm referring to.

I appreciate anyone's input.

boosted91crx

something may have been sucked in and made the marks and damage u see. i wouldnt worry about the housing marks unless they are raised up, if they arent just let them be or maybe sand them a little to get rid of any jagged edges with some light sand paper.

VTECth1s

Got it! I didn't even think about the sanding part for a second. At first I was thinking of bringing the compressor housing to a pro turbo rebuild shop to smooth it out. Thanks!

VTECth1s

Now second thing is balancing the turbo only, no rebuilding it. Since I'll be doing the rebuilding myself. First option is, I've read that you must scribe/mark lines on the comp. nut, shaft, wheel, etc. So that when it's time to re-assemble, you just line up all the marks. And it'll be re-balanced to it's original spec. .

Second option, is getting it professionally done. Now that it's professionally balanced, and I begin the re-assembly. Do I still have to scribe marks on the nut, wheel, shaft when re-assembling the turbo? Even though it was just professionally balanced. Or do I just continue re-assembling it without making any scribes/marks?

VTECth1s

TTT!