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Discussion Starter · #1 ·
I bought a ported stock turbo off the board a little while ago, and I was waiting to put it on until I could get the hot side coated. Well, I finally got some spare $$$ to do it, so I pulled the housing off, and there's a crack inside! I can't seem to post the pic on the BB, so here's a link:

housing crack

EDIT: Added more pics to my yahoo folder so you can see the orientation of the crack better

EDIT2: If you can't get to the pics, I apologize. I'll work on making them visible. Arrrgh.

This will take you to my "RL's Car Stuff" folder, and the one pic in there shows the crack, about center of the image. Sorry about the focus - I'm using borrowed gear and ability.


I want to stress that the person I bought it from is a good guy, and there's NO WAY he could have known about this. This is not a flame post.

The questions I have are: Can I run it like this, cracked and all? Can it be fixed, or would it be better all around to find another stock housing (and have THAT ported - arrrgh)? The ironic part is, I bought this turbo thinking mine was on the way out, and it really isn't. Just call me guru - NOT!

As always, thanks in advance.

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Rhett Lee
Had to leave Hawaii for Oregon, but now I have a Turbo Regal!
If only I could get it to run right...

[This message has been edited by toady (edited August 09, 2001).]

[This message has been edited by toady (edited August 09, 2001).]
 

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Well, since nobody else has responded let me be the first to stick my neck out..


Can you still use it? Yep but I wouldn't recommend it because the housing may only get worse and could cause some damage if it cracks more. You could prolly use it until you got a new one ported, tho.
Can it be fixed? Yes it probably can be fixed but prolly at a much higher cost than a new one
ie...welding then machining...

I would port another one and try to smile about it

By the way, how is it ported? I've been wondering where to port the exhaust housing if possible. Can you post any picks of a ported vs non-ported exhaust housing?

GOOD LUCK
Kevin

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87GN, 12.05 @ 111, SIXTY FOOT 1.60-LAUNCH 15#, BONE STOCK LONG BLOCK, STOCK I.C. (BELL MOUTHED), STOCK TRANS/CONV, Stock Turbo, 009'S, RED'S 107 CHIP. HOME MADE 3" DOWN PIPE. RUNS CONSISTANT 12.10'S-12.11'S.

http://www.geocities.com/kdslaby/solidworks.html
 

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In cases like this, I suggest talking to John Craig at Limit Engineering and seeking his advice. He is a straight arrow and won't tell you to do what you don't need.
 
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Rhett,

Where exactly is the crack? Is it in the exhaust housing, right in the middle leading down into the uppipe?

Both my TA49 and stock turbo have a crack in that area. When I asked the local turbo builder about this he said all Garret housings crack here and it is okay to use. He even said that they used to get hte factory replacements from Garrett and they had that area cracked quite often.

He said that the turbo's on our cars don't spin fat enough or make enough heat (compared to a big deisel truck) for this to be a problem. He also mentioned that you do not want to weld the inside of the housing, because that is when the problems will start.

I don't know if this is the same area you are referring to or not. I cannot verify 100% what this guy said, but he knew exactly what I was talking about as soon as I called and did not hesitate with his explanation, so I don't think he was bs'ing me. He has built dozen's of turbo's for the guys in my local club so hopefully he knows what he is talking about.


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Clayton
87 GN: 307FP hotwired, adj FPR, Tomka Cold air kit,TA49, MSD 50's, CAS V4, 3"DP, Jim Testa street and Lubrant 110 chips Turbolink with boost sensing,
Best ET: 11.79 @ 116 mph, 1.61 60'
 

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Discussion Starter · #5 ·
Thanks all for the replies.

Kevin, I have a friend into SVOs, and he said exactly what you said. Trying to fix this one, if it is bad, will be much more hassle than locating another good one. As far as the porting, I didn't do it. That's a bit beyond my ability.
I can try to take some pix when I swap turbos. After getting this all worked out, of course.

Steve, I will call John Craig and get his opinion.

Where exactly is the crack? Is it in the exhaust housing, right in the middle leading down into the uppipe?
Clayton, I think my best course here is to explain it in terms of the picture. In that photo, the upper left is the scroll that bolts to the header (the 3-bolt part). And we're looking at the "inside" of it, the part that faces the wheel. It sounds like we're talking about the same section, though.

I can take some pics with different perspectives and send them to you. Will that work? Now that you and I are experts in sending digital photos of TR parts to each other, LOL.

Rhett
 

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Discussion Starter · #6 ·
I e-mailed the pix to TurboMike today and he says it's normal. Clayton, thanks for bringing this info to light, and thanks again to all for your help.

Rhett
 

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Originally posted by KEVINS:
Well, since nobody else has responded let me be the first to stick my neck out..


Can you still use it? Yep but I wouldn't recommend it because the housing may only get worse and could cause some damage if it cracks more. You could prolly use it until you got a new one ported, tho.
Can it be fixed? Yes it probably can be fixed but prolly at a much higher cost than a new one
ie...welding then machining...

I would port another one and try to smile about it

By the way, how is it ported? I've been wondering where to port the exhaust housing if possible. Can you post any picks of a ported vs non-ported exhaust housing?

GOOD LUCK
Kevin

If you look at where the stock turbine housing mates up to the header...where the three bolts hold it on there... You'll see that the inlet of the turbine housing where the header dumps into is smaller by quite a bit than the oulet on the header..

What I did was basically port out the inlet on the exhaust housing so that it was a tad larger that the oulet of the header... and then I also ported out as far into the inlet of the turbine housing as I could to try and remove metal and open it up [make it physically bigger inside there..].

I guess my theory for that is... if you really port out the inlet of the turbine housing as far into the inlet as you can.. You're incresing the velocity of the exhaust gases passing through the turbine wheel b/c you have the inlet really ported out as far in as you can reach, at which point it gets small just before the exhaust gases hit the turbine wheel... [i'm prolly wrong tho - I usually am
]

Also I'm going to send you a picture.. of something else I did to my stock turbo that was suggested to me by another list member..



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Steve Ruston
1987 Turbo Limited
 

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Your porting sounds logical and that's what I was going to do to mine but it was way to hot outside for me to mess with at the time. Did you match it to any gaskets by chance?
I did blend the inlet bell and it looks better that way.

KS

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87GN, 12.05 @ 111, SIXTY FOOT 1.60-LAUNCH 15#, BONE STOCK LONG BLOCK, STOCK I.C. (BELL MOUTHED), STOCK TRANS/CONV, Stock Turbo, 009'S, RED'S 107 CHIP. HOME MADE 3" DOWN PIPE. RUNS CONSISTANT 12.10'S-12.11'S.

http://www.geocities.com/kdslaby/solidworks.html
 

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You've probably read this already but just in case
http://www.gnttype.org/techarea/turbo/turboport.html

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Steve Wood

Growing old is mandatory; growing up is optional.


86 GN bought new, 87 T-type-81 El Camino with GN drive train-basically stock 86, 94 Caprice 9C1, 69 SS396 Camaro Convertible
 

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Actually I haven't.. THANKS! I may get bored this weekend and do some more porting


KS

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87GN, 12.05 @ 111, SIXTY FOOT 1.60-LAUNCH 15#, BONE STOCK LONG BLOCK, STOCK I.C. (BELL MOUTHED), STOCK TRANS/CONV, Stock Turbo, 009'S, RED'S 107 CHIP. HOME MADE 3" DOWN PIPE. RUNS CONSISTANT 12.10'S-12.11'S.

http://www.geocities.com/kdslaby/solidworks.html
 

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Discussion Starter · #11 ·
UPDATE: In the spirit of sharing fixes to old problems, I was still a bit worried about using this housing, so I finally made time to call John Craig. What a nice guy! I'm definitely sending any turbo work to him.

His words to me: "100% of them crack. I'd be surprised if you found one that WASN'T cracked." He said that in addition to cracks where c&cgn and I described, it was not at all uncommon to find them near the WG hole. He said not to worry about it.

He also added that if you have it coated, don't let them coat the area just inside the 6 mounting holes, where the housing will meet up with the CHRA/turbine wheel. Tolerances there are tight enough that it may not fit right.
 

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He is a nice guy and he does know his stuff.

That is good info for all of us to keep filed away. Thanks for sharing it.
 

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I'm glad you brought this thread up. I was dismanteling my old turbo last week and the turbine housing had a crack also! It was MUCH larger than yours and it went lengthwise for about 1". It actually looks more like a casting flaw but I wasn't all that interested in the crack so I didn't spend a lot of time looking at it.

Now we know..

KS

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http://www.geocities.com/kdslaby/Diary_of_a_GN_page_1.html


87 GN
12.05 @ 111, 1.60 60', 15psi launch
RA107

New mods: No times yet
JJ 62mm
MaxEffort, 22psi
Race fuel only for street
No more 92 octane for this car:)

http://www.geocities.com/kdslaby/solidworks.html
 

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Discussion Starter · #14 ·
Originally posted by KEVINS:
I'm glad you brought this thread up. I was dismanteling my old turbo last week and the turbine housing had a crack also! It was MUCH larger than yours and it went lengthwise for about 1". It actually looks more like a casting flaw
Yeah, I forgot, John said that these are casting flaws and not stress cracks. I guess that's why it's not a big deal.

but I wasn't all that interested in the crack so I didn't spend a lot of time looking at it.
Yep, just say no to crack!

(I couldn't resist)
 

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Originally posted by toady:
Yep, just say no to crack!

(I couldn't resist)
Break a plumber's heart!
 
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