Wondering why my manifold to turbo bolts keep breaking?

[project_tsi]

This is really starting to get on my nerves.

I recently installed an SBR G50 turbo. I then went to remove the turbo about 2 weeks later due to other issues. When removing 2 of the manifold to turbo bolts, they snapped clean off. Also one messed up the threads but it still came out. No, I did not use antiseaze, which I should have, and I did not over-torque the bolts in.

So, instead of having my turbine housing drilled out and re-tapped for new bolts, I just decided to buy a Bullseye cast steel housing instead. The SBR unit is cast iron, and I really like the dimensions and overall quality of the bullseye unit better. I also bought new APR M10x1.25mm bolts to use, instead of buying stockers, or using cheap grade 8 bolts that would stretch with the heat. +

So now I've got a brand new turbine housing and new ARP bolts to use, and a bunch of anti-seize, just to be safe when using a steel unit. I installed everything, and snugged in the new ARP's and torqued them to spec, even being a little easy on them, and using plenty of anti-seize that Dan at Bullseye gave me.

This is 3 days ago when I installed all these new parts.

Well today I needed to remove the turbo again, to access my 02 housing, as well as clock my turbo out a little further for my IC pipe to clear my dump tube. But wouldn't you know it, 2 of my new ARP's snapped clean in half right at the flange, so I can't use an easy out or anything like that. 1 bolt also came out, but killed the threads for some reason, and one bolt came out OK.

Whats weird is that all my o2 housing bolts came out fine, as well as my CHRA to turbine housing bolts did too, just my manifold to turbo bolt were F'ed up.

Oh, BTW, I wasn't running like 2000 degrees either, or something stupid like that, that would make the bolts hot seize in there. All it took was 3 days. I only live about 2 hours from Bullseye.

Any suggestions on what is causing my bolts to break off? Or what I can do to stop it from happening again? Anyone think bullseye would be nice enough to just trade me out for a new housing, considering it is only 3 days old, I used plenty of antiseaze, and even used new, high grade bolts? I honestly don't feel that this was my fault, and I definitely don't wanna be out another $220. Anyone think that heli-coiling all of the bolt holes and re tapping them to a M10x1.25mm pitch would hold up OK, with the heat and all?

Thanks for all the help in advance, and sorry for the long post, I just wanted to be very descriptive for y'alls.

-Dan

 

[2GSpeed]

i had my stock turbo helicoiled and it held to 18psi solid untill i swapped to a evo III turbo

 

[oldman]

Maybe the turbo is touching something, like the water pipe, causing excessive tension/pressure on the bolts once it's tighten down.

 

[blue1]

Have you still got a piece of flex exhaust in your engine pipe? if that is not there it will do what probs you have!

 

[project_tsi]

Maybe the turbo is touching something, like the water pipe, causing excessive tension/pressure on the bolts once it's tighten down.

The turbo is not touching/ rubbing anything. In fact, w/ the bullseye housing, it spaces the turbo out another 1/2 in at least. Also my downpipe bolts right up, no tweaking, or anything getting it to fit. My oil drain is not the culprit either. I have 2 45 degree fittings for my drain, and they line up almost perfectly, I just use a short piece of 5/8 hydraulic hose for the very small amount of flex. Besides, I bolt up the turbo before I hook up anything else, so Im positive I didn't mess up any threads during installation.

 

[project_tsi]

Have you still got a piece of flex exhaust in your engine pipe? if that is not there it will do what probs you have!

Yes, there is about a 12" peice of 3" flex section right in my downpipe.

 

[project_tsi]

i had my stock turbo helicoiled and it held to 18psi solid untill i swapped to a evo III turbo

Thanks, thats good to know. I think I'm gonna give the helicoil kit a try today, Ill let you know how it turns out. I hope it will hold the heat ok, considering the kits are made to go in heads, and spark plugs.

 

[timawdtsi]

I had a st of the ARP turbo bolt's do the same thing to me as well with an EVO 16G housing. I had the engine just on the stand for assembly mock up ( I was running the AN oil lines for the turbo) and upon the removal of the bolts they jammed up. The bolt's were only threaded in with a short stubby wrench and to remove they started to unthread and then became very stiff. At that point I tried running PB blaster down the bolt holes and working them loose but with no success. Ended up just having to snap them off.
Just wondering was it the chrome ARP bolts you were using?

 

[Quasimondo]

What order are you guys going when you bolt everything up? After countless bolt breaking experiences, I find it better bolt the collector and exhaust manifold up first before you put anything else back in. If you do these last, the exhaust housing won't be as squared up to the manifold and the extra stress you put on those bolts to tighten everything up to get a good seal can be enough to snap those bolts.

 

[project_tsi]

Just wondering was it the chrome ARP bolts you were using?

No, I used the black oxide coated ARP's. The SS ones were about double the price, and I didn't think it mattered, the coating that is.

Im not home right now, im at work, so I cant measure my good bolt, but what is the length, in mm of the turbo to manifold bolts? I cant remember and Im out buying new ones later. I know its M10x1.25 but what length? Thanks, dan

 

[project_tsi]

What order are you guys going when you bolt everything up? After countless bolt breaking experiences, I find it better bolt the collector and exhaust manifold up first before you put anything else back in. If you do these last, the exhaust housing won't be as squared up to the manifold and the extra stress you put on those bolts to tighten everything up to get a good seal can be enough to snap those bolts.

Yeah I bolted up like so. W/ no extras on first. I mocked it up, and bolted in the ARP's, in a criss cross pattern to get even pressure. Then I hooked up the oil feed, and drain, and then the down pipe to o2 housing, and like said before, nothing had any resistance or pressure or trouble when installing it all.

 

[Zex4g63]

The gasket between the mani and turbo can get deformed. While you have it apart see if lines up with all the bolt holes. Many times it is touching the bolts causing the threads to get messed up while you are installing them. Just file the bolt holes of the gasket to gain clearance. Now I use only a little oil to install them and the come right out when I want them too.

 

[project_tsi]

The gasket between the mani and turbo can get deformed. While you have it apart see if lines up with all the bolt holes. Many times it is touching the bolts causing the threads to get messed up while you are installing them. Just file the bolt holes of the gasket to gain clearance. Now I use only a little oil to install them and the come right out when I want them too.

Ok Ill check out the gasket, althought I dont suspect it to be the culprit. I use SBR's 7cm thick steel gasket, but Ill check. Now do you use antiseaze as a lube too, or only use some oil, or both?

What length, in MM, are the turbo to manifold bolts?

 

[RoasT BeeF]

Mine break every single time I take the turbo off also. At least 3 will break off everytime. If Im lucky, 1 will come out but jacks up the threads in the process anyway. Ive had to heli-coil my last 2 turbos and they all held up fine.

 

[project_tsi]

Mine break every single time I take the turbo off also. At least 3 will break off everytime. If Im lucky, 1 will come out but jacks up the threads in the process anyway. Ive had to heli-coil my last 2 turbos and they all held up fine.

Thats good to know. Where did you get the helicoil kit? Do your bolts keep breaking even w/ the helicoil kit? Approx. how much is the helicoil kit?

What length, in MM, are the turbo to manifold bolts?

 

[2GSpeed]

I got my helicoil kit from CarQuest and it was 20 bucks

 

[Zex4g63]

Ok Ill check out the gasket, althought I dont suspect it to be the culprit. I use SBR's 7cm thick steel gasket, but Ill check. Now do you use antiseaze as a lube too, or only use some oil, or both?

What length, in MM, are the turbo to manifold bolts?

I use no antiseize and I have the worst luck with aftermarket bolts. I use only OEM now.

 

[Maglin]

I too have had problems with bolts snapping off. I have the bullseye housing for my HX-35. Used new bolts with 2 washers each to ensure I wouldn't bottom out on the shank of the bolt. I torqured them to 30 ft/lbs. Broke 3 bolts tring to remove them. The 4th bolt once it was loose (about 2 turns) came out by hand. The other bolts also started to come out by hand and then all of a sudden siezed up. I had liberial amounts of copper antisieze (locTite brand) and the turbo was only on for about 3 weeks. I'm planning on taking the turbo off again here in the near future and I plan on using my torch to get the housing pretty hot and then try to remove the bolts. I think the housing slightly shrinks and slightly deforms which causes this issue.

I've also heard that if you helicoil your TH that you might never have this issue again. I think it's mostly due to the fact that their is more room for expansion and contraction between the bolt threads and the TH w/ the helicoil's in their.

I've also had this happen when just mocking up the turbo. I didn't even tighten it down with a wrench. It was just finger tight so the turbo wouldn't move. Broke one bolt. I honestly don't think that bolt strength is the issue.

 

[99gst_racer]

Dan - I beat you. I just got done breaking all four..... This sucks ass. I'm going to the machine shop tomorrow to see if I have any luck; I'm also going to call Dan over at Bullseye. I just dont feel like driving all the way up there. And I have to get this taken care of before the shootout at the end of the week.....

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I plan on using my torch to get the housing pretty hot and then try to remove the bolts.

Well, I just kinda tried that. I figured they would come out easier when hot, so I drove my car spiritedly for about 10 min then pulled into my garage and tried to get them out. When cold, the bolts simply break, and when hot, they bend. Check out this pic. This is not threaded into the housing like this.... The head actually bent over from me threading them out while hot.

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I honestly don't think that bolt strength is the issue.

I dont think it's bolt strength either..... But it's not just the Bullseye housing either..... People are breaking off ARP bolts as well as stock bolts.... And Dan (the thread started) had this same thing happen to his SBR housing a couple weeks ago. Not really sure where the problem lies, but this definitely sucks.

 

[Keshav]

just posing a theory:

could it be that ARP bolts along with the others do not handle the 1400-1600 degree exhaust temps as well as the OEM mitsu turbo bolts because they are not made of the correct steel for the job? Perhaps there is a specific grade of bolt made for this application that employs some additive to the steel (tungsten?) that allows it to withstand not only the heat, but the heat cycling without weakening.

that picture of the bent bolt along with people's experience with the threads being ruined from _removing_ a bolt make me suspect that this is the case.

anyone knowledgable about metallurgy, please step forward.

 

[RoasT BeeF]

I too have tried heating up the housing/manifold before removing the bolts and had the exact same result as 99gst_racer. The bolts bend, and then they are even harder to get out. I have almost found it easiest to just have the bolt snap off right away instead of fighting it all the way out.

I think my next quest will be to buy some longer, thinner bolts and slide them all the way through and put a nut on the end.

 

[oldman]

Just a thought. I have now done many turbo swaps, the original 14b, taken off the small 16g at least three times, then most recently remove the GT12 off my car after some test runs, went through 3 sets of bolts (2 oems and 1 ebay) and I have never broken any bolts or strip any housings. Keep in mind that I always use anti-seize (except for the original removal of the 14b) and soak them with pb blaster before my attempts, maybe I'm just lucky.

After reading the respones in this thread, it seems that most of you except for one person with a sbr housing, all have one thing in common, the Bullseye housing. I have also read in other similar threads and the name Bullseye seems to pop up a lot. I'm not saying the housing is the problem as I don't even own one but I think it definitely deserves further investigation.

 

[yangtech]

i took out my AGP 60-1 turbo and i just broke two bolts also, only been in there for not even a month... where do i buy a new turbo housing at if i need to..?

 

[99gst_racer]

just posing a theory:

could it be that ARP bolts along with the others do not handle the 1400-1600 degree exhaust temps as well as the OEM mitsu turbo bolts because they are not made of the correct steel for the job? Perhaps there is a specific grade of bolt made for this application that employs some additive to the steel (tungsten?) that allows it to withstand not only the heat, but the heat cycling without weakening.

that picture of the bent bolt along with people's experience with the threads being ruined from _removing_ a bolt make me suspect that this is the case.

anyone knowledgable about metallurgy, please step forward.

The ARP's definitely cant hold up to 1400-1600 degrees. But keep in mind, just because the exhaust gas is 1400 degrees, does not mean the metal is getting that hot. I recently spoke with one of the technitians at ARP on this subject. He told me that they dont recommend using their ARP bolts on surfaces that heat up above 800* F. He said that they may work past that, but they arent designed for it. I honestly feel that is it a problem with the thread tollerences with the casting itself. The tolerence is too tight and the cast housing will slowly and slightly deform from the constant extreme heating and cooling. Only problem is that if they 'loosen' their tolerences with the thread casting, then that will take away from the "thread bite". Then people might have problems with pulling the threads out and stripping the housing. It's a trade off.

I'm taking mine to Bullseye tomorrow. I'll see what Dan says when he sees it. If he can get the bolts out, I'll be surprised. I might need a new housing now.....

I think my next quest will be to buy some longer, thinner bolts and slide them all the way through and put a nut on the end.

I thought about doing that also. I know of many people that chose to do that on their Mitsu. housings. The bad thing is that there is not enough clearance on the Bullseye housing for a nut on the bottom side....

 

[RoasT BeeF]

I thought about doing that also. I know of many people that chose to do that on their Mitsu. housings. The bad thing is that there is not enough clearance on the Bullseye housing for a nut on the bottom side....

Ah yes, but there is on the good ol Evo 16g housing.

I too think it has something to do with the constant extreme temp changes that the bolts see. I have noticed that after the holes are heli-coiled the bolts do seem to come out easier no matter how long they have been in there or how new/old the bolts are.