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Fasteddie313 · Joined: 29 Sep 2013 Posts: 2595 Location: MI

Took another big hard run with a passenger last night, everything went fine.. Ran awesome..
Cruised for about a mile, turned around and went to go back, "HOOOOOOOT" like an owl and no boost
It still ran awesome just lost all boost, I thought I blew a hose somewhere.. Today I started taking hoses off to find the leak/rip whatever and I find this..

The shaft nut backed off and was just barely on when I found it, that let the comp wheel slide up the shaft a bit and it ate the comp wheel against the comp housing, the shaft is even bent..... TOAST/FUBAR

Maybe it had something to do with its oil drain vibrating against my crossmember, shook it up too much or something.. It's definitely my fault whatever happened, I put it together..
This thing was all like brand spankin new guts a couple months ago, now I have to start from scratch.

Maybe she will live again next spring or something, It's going to take me a while to save up to put together another turbo and have it done proper..

Then my engine will blow and I'll have to rebuild that and still have to rebuild my G31..

depressed
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80 Turbo - Slightly Modified

jason c · Joined: 13 Jan 2014 Posts: 1018 Location: Nwi

Well, that sucks.
What did you torque the nut to & did you loctite it?

Fasteddie313 · Joined: 29 Sep 2013 Posts: 2595 Location: MI

I torqued the nut back to where the nut/shaft/comp wheel lined up as before to keep its balance the best I could..

No loctite, my first thought when I saw it, should have used loctite..
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80 Turbo - Slightly Modified

jason c · Joined: 13 Jan 2014 Posts: 1018 Location: Nwi

I always use it, can't hurt. I never had one come loose either.

leadfoot · Posted: Sat Jul 25, 2015 8:24 am Post subject:

Yeah its a setback and a bummer but live and learn,
My last engine got destroyed from shearing the timing gear dowel, a simple change to solid pin or two for that matter would have saved it....

car projects always cost, could have been worse sending something through the engine if that nut had come off...

and rebuild your waste gate diaphragm properly when you take the turbo out

a simple tip for anyone rebuild parts/installation make a list of things to do before during and after work has been conducted...
check critical bolts and nuts, filler caps/drain plugs, electrical connections/hose connections...

seems simple but we've all done it at one stage...even mechanics do it...
chin up mate...
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1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

Fasteddie313 · Joined: 29 Sep 2013 Posts: 2595 Location: MI

I'm pretty sure I have 1 good 931 turbine wheel/shaft left, send that to a shop alongside a k26/6 with a good compressor and get back a water cooled turbo that will bolt up with a slightly larger compressor that I can spit upside down..

Or I could use one of my 931 bearing housings, and shaft/wheel, and see if I can find a shop that has a k27 coldside in stock (reasonably priced) to send them to to get a big compressor but I'd still not have water cooling..

Maybe I'll find a deal on a good to go k26/8 and bolt it on but that's unlikely..

A new 2664 comp wheel + my parts and rebuild kit should put me right back to what I had + a shop balance/rebuild, I doubt my Audi comp housing is hurt too bad.. But I wouldn't mind my boost coming on a few rpm higher for some more headroom and efficiency gains..

I was testing that thing up to 1bar and it didn't feel like it wanted to quit there, my intake never got hot that I could find, and I never heard a hint of pinging ever..

An OEM 931 compressor housing is out of the question, it must be a standard non-931 comp housing so I can shoot it down to my FMIC plumbing.. (I have both S1 and S2 comp housings anyway and a good S2 wheel but there no good to me now)

What do I want to do now?
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80 Turbo - Slightly Modified

SlayerSST · Joined: 21 Sep 2010 Posts: 212

The Rise and Fall of Fasteddie313

September 29, 2013 - July 24, 2015

Fasteddie313 · Joined: 29 Sep 2013 Posts: 2595 Location: MI

We'll see about that... More like a healthy correction in an uptrend..

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80 Turbo - Slightly Modified

Fasteddie313 · Joined: 29 Sep 2013 Posts: 2595 Location: MI

The pistons and rings are unharmed, they look perfect..
The bearings are perfect, you can still see the cross hatch style marks on the inside of them, virtually no wear..

The only part of the shaft that looks bent is the last 3/8" of the threaded part, the collar the comp wheel sits on looks to be true still..

I will set it up with my dial indicator and check the shaft for runout

I am confident this turbine wheel/shaft can be salvaged by a shop, its still very nice and they can straighten them.. I have another good one anyway I believe..

The turbine wheel has no damage, it touched the housing but I think only from me trying to make it to see if it would/did..

After the autopsy, what I think happened..
Nut came loose..
Comp wheel slid off a tiny bit and hit the housing..
The shaft spun inside the comp wheel blowing out its hole..
The comp wheel cocked on the shaft after being blown out inside throwing out the balance and exaggerating everything..
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80 Turbo - Slightly Modified

Carrera RSR · Joined: 08 Jan 2010 Posts: 2312 Location: Somerset, UK

Well that was an anti climax. I was expecting a holed or melted piston from a massive over boost and det event based on the title

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1980 931 - forged pistons, Piper cam, K27/26 3257 6.10 hybrid turbo, 951 FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife
Now www.924board.org/viewtopic.php?t=34690
Then www.924board.org/viewtopic.php?t=31252

Fasteddie313 · Joined: 29 Sep 2013 Posts: 2595 Location: MI

Sorry to disappoint, the engine is still solid (I think).. No noises or clunks/knocks/clicks etc but still the same unimpressive hot oil pressure that I can't figure out why.. Even stethoscoped all over the engine and don't hear squat other than my cam (which needs replaced).

I'll be looking for a replacement cam/buckets set soon, a couple lobe tips look like crap but all the bucket surfaces are still very nice looking, no change since I bought the car.. I've been in there 3 or 4 times now to check on things and adjusted lash once.. I just can't fix everything at once but things are rising to the top and now I know I have a solid package worthy of some real investment..

I am seriously considering pulling the pan and plastigauging all the main and rod bearings and possibly replacing some, if not all of them.. Also plastigauging the cam bearings, and pulling and inspecting the oil pump spring and plunger thing.. Pretty sure I will do this next before the car runs again..

I would also like to pull the head and pistons for inspection purposes and to hand lap the valves a bit just because but there's no real reason to do that other than looking for trouble.. Maybe I will if I can reuse my head studs but I don't know yet.. I don't want to spend another $200-$300 to put the head back on just because I'm curious..

I thought about a title like "guess what blew up first" for this with a poll but didn't..

Back on turbo topic, I scored a k26/6 already that will get a 931 turbine wheel/shaft and 931 turbine housing, So I'll be running a bit bigger compressor and a water cooled bearing housing soon/next..

So much for my budget going to a wideband and tires...
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80 Turbo - Slightly Modified