Where's the boost?

[The_Josh_Bear]

Josh, why would loose turbo bearings cause a lack of boost? You went from 5 to at best 6 with the new cartridge. The defective wastegate seems to have made all the difference and then the increased fueling made even more boost). If the impellers were scraping the housing that should be obvious and a horrendous noise, or maybe it had clearanced itself by the time you got the used turbo...

Wes already answered this some but the wobble is tight for one thing and progressively worse for another. Meaning that it just barely grazes the housing when it does touch and then just slowly gets worse and worse. Due to the oily intake of our setups the untrained eye couldnt even tell the compressor was touching the sides because there was no marring, it was all smooth.
BUT take off the intake and rev the engine and you could see it wobbling all over, it was crazy. I would have linked the video but somehow its deleted off my drive.
For the turbine side that was scraping too but there really wasn't a noise to be heard over the engine rattle and turbo spool that I could hear.

 

[DrCharles]

OK thanks. I have rebuilt a couple of turbos before, so it doesn't scare me (as much as having to R&R it again!) I'm thinking of just buying a cartridge (CHRA) rather than getting a bearing & seal kit, taking it apart and find out something else is scored/damaged.

 

[Thewespaul]

Get a chra from a good trusted source, the ones on eBay are not a quality rebuild. You can get the turbo rebuilt by Russ or me for cheaper than the chra would cost and it would be balanced. R&D sells a chra if I remember right with a ww2 installed

 

[DrCharles]

How much $ are we talking about? PM me if you don't want to post prices here

 

[Thewespaul]

A basic rebuild you would be looking at ballpark $450 shipped to your door, we can do the high performance rebuild for an additional $100 that will have the stepped gap piston ring and 360* thrust bearing. Machining the housing for and installing oversized modern wheels is about $250 per side depending on wheel choice. A chra from Justin is $525-685 if you want to go that route

 

[DrCharles]

That's in line with most of the rebuilder services I found online.

The $230 (shipped) CHRA's on eBay claim to be balanced and have a warranty, like this one:
https://www.ebay.com/itm/1992-1994-...305-Turbo-charger-CHRA-Cartridge/253253595568

What about them is not good quality? The parts or a high-volume offshore production line?

 

[FordGuy100]

Both. It could last, it could not. I'd hate to get one and then a year later be forced to buy another because chinesium CHRA #1 spilled its guts. But if your in a tight spot then its always an option.

I'd probably hold off till you are sure there isn't something else (that is less costly) awry with your setup.

 

[DrCharles]

I'd probably hold off till you are sure there isn't something else (that is less costly)

Well, yeah But there isn't much left that would explain the symptoms! I now have enough fueling to make black smoke (and with high EGT), can't find any exhaust or intake leaks, can't get over 7 psi, and I know the bearings are way looser than the specs...

I've already put a fair bit more into this pig-in-a-poke than the purchase price 15 months ago. It's much improved over the no-maintenance abused farm truck it was when I got it. My wallet is saying to back off

 

[IDIBRONCO]

Maybe a Wicked Wheel? I don't know what's all involved with installing one.

 

[Thewespaul]

Play with the timing

 

[DrCharles]

I can try that too. Would you recommend advancing or retarding it? Supposedly it's set to factory NA (8 deg) now.

There is a very audible difference when the cold advance is on (rattle) and the engine is much quieter once it warms up and shuts off the advance.

 

[austin92]

If it is actually 8 degrees, I couldn’t see any issues there. It’s probably lower since they retard timing as they wear. I’ve read on here a lot that turbo engines like 7-8 and na likes 8-9


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[Oledirtypearl86]

Reading this you had about of grey smoke if it was mine an didn't have a timing meter I'd bump the timing up a 1/2 dime width till you got a little clatter on idle. I read here on ob to use a punch to mark your original timing by punching a mark on the seam between the pump and gear cover

 

[DrCharles]

Would jumpering the cold advance solenoid (to stay on) be too much advance for a test?

I've got a Mac Tools box that triggers off a line clamp, but I don't own a dial-back timing light. Before moving anything, I'd definitely mark the pump flange to make sure I could get it back where it was

On a turbo gas engine, retarding the timing gives a hotter exhaust which helps spool up the turbo quicker. I assumed the effect would be similar on a diesel - more energy going out the exhaust? The recommendations seem to be for more advance though (including the factory spec, about 2 deg more advance)...

 

[austin92]

Would jumpering the cold advance solenoid (to stay on) be too much advance for a test?

I've got a Mac Tools box that triggers off a line clamp, but I don't own a dial-back timing light. Before moving anything, I'd definitely mark the pump flange to make sure I could get it back where it was

On a turbo gas engine, retarding the timing gives a hotter exhaust which helps spool up the turbo quicker. I assumed the effect would be similar on a diesel - more energy going out the exhaust? The recommendations seem to be for more advance though (including the factory spec, about 2 deg more advance)...

Just for a short test, it’ll be fine. I think Wes was saying on one thread that it messes with the metering valve so its not a good thing to do all the time.


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