Exhuast studs and anti-seize question

[bemis]

I'm replacing all the exhuast studs on the beater while I do the na to turbo swap. Luckly, none of them broke off. I guess having an engine with only 70K on it helps.





Should I use anti-seize compound or something on the studs before I start putting the newer ones in?

Side note: It is sooooo much easier to work on a Z when EVERYTHING has been removed from the engine bay that is not needed to keep it running and legal on the streets. I have sooooo much room to turn a wrech its almost scary.

[MrwassmanNA2T]

I would antiseize them, as i did mine

[Dan-TSS]

*The studs breaking is not an issue of the threads binding.
~You should anti-sieze anything steel threading into aluminium anyways.

**The resolve to the issues of broken studs is to swap to a metal that can better tolerate the heat cycling that the hardware sees.(such as my Stainless Steel replacements kit)
The oem type metal studs tend to temper and become brittle from the heat cycling they see when running the higher EGT's created from the turbo application.
Dan 8)

[MrwassmanNA2T]

Yeah, i am sporting the TSS Bolts 8)

Supposedly turbos also make a frequency that matches that of the stud and breaks them :roll:

[Dave88SS]

MrwassmanNA2T wrote: Supposedly turbos also make a frequency that matches that of the stud and breaks them :roll:

Doubtful. The harmonics of the engine itself are more likely than the turbo harmonics. If the turbo was transmitting enough vibration to take out the exhaust studs, it would be playing havoc with the turbo itself.

Even then, the harmonic would have to occur at highway cruising rpm. That would be just flat out bad engineering.

[bemis]

I would think that the added weight of the turbo and the added heat would put stress onto the studs and that is what makes them snap.

I noticed on the Chrysler Lebaron 2.2L turbo'd engines that the turbo was supported from the bottom by a study bracket which reached to the bottom of the block. I guess Nissan should have done the same thing. And maybe we should too, especially those with big turbos.

[MrwassmanNA2T]

yeah my buddys supra has a brace from the engine mount to the turbo and from the head to the turbo.

Kinda found that interesting + the down pip is supported with a heavy bracket.

[2+2turbo]

i'm planning on one of these when i do my one-off exhaust for the holset .


http://cgi.ebay.com/ebaymotors/NEW-EXHA ... 8131QQrdZ1

[Firehawk]

Dissimilar metals cause dielectric corrosion, so anti sieze should alwasys be used.

[Jason84NA2T]

Firehawk wrote: Dissimilar metals cause dielectric corrosion, so anti sieze should alwasys be used.

Agreed. Be sure to use the high-temp stuff so it won't gob up as badly from the heat.

The real issue with broken studs is always going to be heat cycling and the material fatigue related to it. The original yield strength of the stud can decline quite rapidly as it is put through cycles, and at different rates. This is one of the reasons selecting a fastener rated for the type of duty you are intending is important independently of its strength out of the box... You can see they revised the 8mm studs a few times before probably deciding a bigger stud (10mm) was the solution when they made the VG33.

[G-E]

my feeling is the lack of a flex coupler or a sprung flange in the mid pipe is the problem, it causes too much stress on the studs instead of relieving it by flexing