Exhaust: use hex bolts instead of studs?

[Vipergrün]

Hello all,

in preparation for installing early heat exchangers on my SC, I am wondering if an 8mm hex bolt could be used in place of an exhaust stud and 8mm hex barrel nut. Anyone ever done this? Seems like it would be easier to deal with, with no more possible broken studs. The hex bolts I am referring to have a head that look like a hex barrel nut.

cheers
-Brad
80SC

[EWPurdy]

It's my (very) limited understanding of the physics of fasteners that studs and hex bolts are not "The Same" from a mechanical point of view. Furthermore, studs are generally more friendly to aluminum heads since they do not need to be removed every time the part is removed thus reducing wear on the the relatively fragile threads.

[Superman]

Removing studs from heads is something that experienced folks don't do any more often than they have to. Apparently, chances are excellent that they will break.

[Vipergrün]

Originally posted by Superman
Removing studs from heads is something that experienced folks don't do any more often than they have to. Apparently, chances are excellent that they will break.

.......unless they come out anyway I went ahead and removed all of the nuts and barrel nuts, 4 studs came out with the barrel nuts. Since I'm putting on the thin-flanged HE's, I'll probably get the shorter studs for at least those 4 and use spacers with the other 2. The case side of the studs were perfectly clean, no rust at all.

Should I use a good anti-seize when I put them back? I have some copper-based stuff.

PB Blaster, torch and patience does it..

cheers
-Brad
80SC

[A Quiet Boom]

I've been running aluminum parts on my race motors for years (Ford) and I absolutely do NOT recommend going to bolts instead of studs. A great deal of damage can be done to aluminum parts when trying to remove bolts. Also when you tighten a nut on a stud the force is evenly distributed across all the threads in the head vs. the turning force exherted on the threads with a bolt. I also run ARP studs for my main and head studs with cast iron blocks for this very reason. Torque is more evenly applied and the chance of thread damage is drastically reduced. I'd reinstall them with either anti sieze or Loc-tite blue which is formulated for use with studs in aluminum parts. Just my two cents that cost me several hundred to over a thousand dollars worth of "learning experiences"

[Vipergrün]

Thanks guys, this is exactly the info I was looking for.

-Brad