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easy exhaust mani mod

this is a simple mod i did because i was tired of suds stripping out. all it is is a harded 1" allen head 3/8 bolt and hold up better than the studs in my opinion
 

Barnes

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Personally I'm mixed about this because you are asking a lot more of the aluminum in the head than a stud is.
 

broxma

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While it may be easier, it for sure has less holding strength. The shoulder on the stud forms a seal against the beveled part on the hole. It is this seal that give a lot of the stud its strength. Under any circumstance, an equal diameter stud will be stronger than a bolt of the same size and material. with your solution, you are much more likely to strip a hole than with the stud. The real solution for the stud issue on the manifold is drill the holes on the manifold to accommodate larger studs, the size of the end studs on the intake would be good, then drill and tap the head for the new larger studs, and loctite the studs in.

/brox
 

i understand what your saying but i have had no problems with it at an average of 18lbs of boost and has help up to 25 lbs
 

IncorpoRatedX

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for how long? it's how well it holds up over time that will be the difference.
 

its been a couple of weeks so far and good ile update in a couple more weeks and there is no going back for me unless i get a new head because of them being 3/8 bolts
 

SouthCaliVR4

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I used stainless studs & bronze self locking nuts. I have never had any issues running them or when I've had to disassemble. You will find studs hold better, bolts are gonna back out with heat cycling.

Locktight isn't likely to help given the amount of heat those fasteners are subject to, I would think /ubbthreads/images/graemlins/dunno.gif
 

turbowop

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It'll hold up fine under running conditions. It's when you have to pull those bolts back out that you will have issues. They will probably pull aluminum out with the threads. The aluminum threads in the head aren't meant to have bolts put in and then the twisting force of torque put on them to fasten the weight of the manifold and turbo. With a stud and nut, the nut just pulls on the aluminum threads as it tightens down on the stud. The twisting action adds a force that will strip them bitches out. Good luck. /ubbthreads/images/graemlins/uhh.gif
 

i am not to worried about that because i ever have to remove them i am buting a new head anyways and porting and pollishing it and aftermarket valves and spring, ECT
 

IncorpoRatedX

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so you're saying that you don't care about your destructive behavior, because you intend to throw this head away.

this isnt a simple mod, this is a method of rendering your head useless, much like the one above your shoulders.
 

Andy_S

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Jan 30, 2007
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Shithole Wisconsin
When remove the nuts on a mani thats been there a while, the stud usually comes with the nut. At that point, whats the difference?
 

Launch

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Aug 17, 2006
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More like Easy thread stripping aka not understanding mounting hardware /ubbthreads/images/graemlins/rofl.gif
not even a locking washer?
 

Barnes

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Quoting broxma:
The shoulder on the stud forms a seal against the beveled part on the hole. It is this seal that give a lot of the stud its strength. Under any circumstance, an equal diameter stud will be stronger than a bolt of the same size and material.
/brox



You are going to have to explain this one, because it doesn't seem to make any sense.
 

broxma

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Quoting Barnes:
You are going to have to explain this one, because it doesn't seem to make any sense.



Sure. Two things.

First. The way the beveled shoulder on the stud, locks against the beveled opposite shoulder in the head forms a very tight bond. So tight you could consider it a semi weld. It's not really a weld mind you, but the purpose of that bevel is not just to bottom the stud shoulder out, but to lock it, effectively making it one with the head. This does a few things. One, it makes it a very strong structural component of the head itself and two, preloads the threads of the stud. This bevel and the "semi-weld" characteristic, is of vital importance to the stud itself and partly why it has superior holding strength to a bolt.

Two. Why is the stud of equal size and material stronger? Easy to answer. Threads, therefore surface area. The beveled shoulder has already locked and preloaded the threads on the stud. So all effective force is now between those two surface areas, that is, the entire surface area of the threads and the constant force trying to push them apart. The same holding force would be applied if a bolt were used of the same length however it would not have the benefit of the shoulder therefore it would only load the threads to the torque of the bolt. On the same bolt, on the head side, there is only one surface area. The bottom of the head of the bolt. That is all the holding force that bolt will ever have under any circumstances, ever. The bottom of the head of the bolt. On the stud however, You have both, the bottom of the nut AND all the threads of the nut. More surface area=more holding power. Simple math.

That is a paraphrased version of the explanation I received from Corky Bell when I asked the exact same question.

/brox
 

Barnes

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Do you have a copy of Corky Bell's original explination?
 
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