Exhaust Studs vs Bolts

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Money Pit

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Is it better to use studs or bolts where the exhaust manifold connects to the head pipe? When I removed my exhaust manifold there was a stud, which came out because the nut was locked up, and a bolt. Does it make a difference for exhaust leaks? Thanks
 
No, just use whatever is easiest. I think the factory used studs for ease of assembly. I think I'd keep it that way, for the same reason.
 
Money Pit said:
Thanks, I ended up using bolts for both.
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It depends on the type of metal used in the castings. Bolts to hold an exhaust pipe to the outlet of a manifold is fine but in aluminum heads or blocks bolts can tear out the threads easily when tightening a manifold to a head,in some cast iron this will also happen.I recently worked on a 1938 Bantam for a friend.The previous owner took out the studs that hold the head to the block and used bolts because he liked the look better .I had to put heli coils in 4 of the bolt holes because they were stripped out. With studs the torque is on the end with the nut mostly and with bolts it's on the block.In situations with heat the metal weakens in the threads so you are better off with studs .
 
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valiantwagonguy said:
It depends on the type of metal used in the castings. Bolts to hold an exhaust pipe to the outlet of a manifold is fine but in aluminum heads or blocks bolts can tear out the threads easily when tightening a manifold to a head,in some cast iron this will also happen.I recently worked on a 1938 Bantam for a friend.The previous owner took out the studs that hold the head to the block and used bolts because he liked the look better .I had to put heli coils in 4 of the bolt holes because they were stripped out. With studs the torque is on the end with the nut mostly and with bolts it's on the block.In situations with heat the metal weakens in the threads so you are better off with studs .
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Great info. Thanks alot.
 
The bolts will eventually seize in the holes from electrolysis.......unless anti-seized. ; but this will just delay it, as the AS cooks out.
It should be studs and brass/bronze nuts. These nuts are very soft and when it comes time to remove them,they leave the studs intact.
Before you reinstall or replace the yellow nuts, the studs should have their threads chased.
 
AJ/FormS said:
The bolts will eventually seize in the holes from electrolysis.......unless anti-seized. ; but this will just delay it, as the AS cooks out.
It should be studs and brass/bronze nuts. These nuts are very soft and when it comes time to remove them,they leave the studs intact.
Before you reinstall or replace the yellow nuts, the studs should have their threads chased.
Click to expand...
Will the local auto parts store carry these studs and nuts? Thanks
 
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