Advice on Exhaust Manifold Nuts
#11
Originally Posted by dsddcd,Aug 24 2008, 08:57 PM
What about a Lock washer and loctite, mine have been fine so far.
The stud is the problem, not the nuts. The high heat literally turns the inside of the studs to soft clay (ask me how I know )
#12
Registered User
Thread Starter
Yeah, that's one of many of my problems. I've broken two studs from heat popping them, and my two rear lower studs are now gray they've softened so bad. The stage 8's go in this weekend.
#13
Now, I am not sure exatly what temperature the turbo runs but I am sure most of us will not see a case temperature above 700F with an exhaust temperatures near 1200F. My studs are SST and I am assuming they are of the 304 variety. If that is the case the stud would have to reach some where near 1050F for any grain structure changes. Now, I don't have a TTT diagram for SST 304 but the stud actually being the issuse seems odd. On another point why would this not be an issue on factory produced turbo's?
As far as the stage 8's go I have used them on headers in the past and was happy with the performance. I also like the double nut idea as a nice and easy solution.
As far as the stage 8's go I have used them on headers in the past and was happy with the performance. I also like the double nut idea as a nice and easy solution.
#14
Registered User
Thread Starter
I don't know what's going on but they are definitely turning to butter. They have no case strength after a month or so. It probably has to do with the log. I would imagine it has some hot spots, and the amount of expansion the cast steel sees would probably anneal the studs until they give. I also would love to have 10mm studs. The 8mm seem inadequate right now. The added weight , and the poor fit of the downpipe, probably isn't helping either. Doesn't matter though, the little bastards are history.
#16
Registered User
Originally Posted by SgtB,Aug 24 2008, 10:54 PM
Yeah, that's one of many of my problems. I've broken two studs from heat popping them, and my two rear lower studs are now gray they've softened so bad. The stage 8's go in this weekend.
#17
This is just about common sense, there are plenty of industrial applications with high demands on the nuts.
The two most reliable fasteners in my eyes are anaerobic glue for lowtemp apps and metallic lockwasher or double nuts for high temp apps.
Examples on lockwashers are the common ones that are just cut off and bent or some more refined ones such as a nordlock washer.
Its no magic involved and I would not spend alot on some brand nuts.
Just my opinion. Tightening with torque wrench will help also.
Regards
The two most reliable fasteners in my eyes are anaerobic glue for lowtemp apps and metallic lockwasher or double nuts for high temp apps.
Examples on lockwashers are the common ones that are just cut off and bent or some more refined ones such as a nordlock washer.
Its no magic involved and I would not spend alot on some brand nuts.
Just my opinion. Tightening with torque wrench will help also.
Regards
#18
Registered User
Thread Starter
Haha! Torque wrench! Good luck with that. I can BARELY fit a box end in there. I don't think I could even right angle torque the bottom studs. Nordlocks have been hit or miss. I could probably find some super high temp lock washers, but stainless ones are so weak after two or three runs, I can compress them with two fingers. The stage 8s are absolutely not backing out, and considering it takes 3 hours just to get to the studs, I'll happily pay the premium.
I bought an LS1 kit from my local domestic shop. It came with 13 bolts for around $45. They are 8mmX1.25. You should save yourself some aggravation and order from stage 8 though. They'll be cheaper, and you won't have to cut them shorter.
I bought an LS1 kit from my local domestic shop. It came with 13 bolts for around $45. They are 8mmX1.25. You should save yourself some aggravation and order from stage 8 though. They'll be cheaper, and you won't have to cut them shorter.