Kestas
Staff member
Originally Posted By: clinebarger
Originally Posted By: Kestas
Why are they highly stressed? What is stressing them?
BTW, nearly all fasteners are made with rolled threads.
The manifolds expand & contract so much that it bends the bolts back & forth 'til they break, They can also warp to the point the bolt heads pop off. If the bolt is broke off flush with the head......expandtion got it, If the head is popped off....Warpage is most likely. But as Trav said.....Check the manifolds for flatness. They also support the catalytic converters & y-pipe.
I could have worded the rolled threads comment a little better.....ARP does a better more consistent job at it.
This is a common issue on Texas trucks, It's not just because corrosion of the fastener.
Movement of the manifolds would stress any fastener, plain carbon steel or stainless.
I'm surprised you have such detailed knowledge of fastener threads and fatigue resistance of materials with regard to exhaust bolts.
Originally Posted By: Kestas
Why are they highly stressed? What is stressing them?
BTW, nearly all fasteners are made with rolled threads.
The manifolds expand & contract so much that it bends the bolts back & forth 'til they break, They can also warp to the point the bolt heads pop off. If the bolt is broke off flush with the head......expandtion got it, If the head is popped off....Warpage is most likely. But as Trav said.....Check the manifolds for flatness. They also support the catalytic converters & y-pipe.
I could have worded the rolled threads comment a little better.....ARP does a better more consistent job at it.
This is a common issue on Texas trucks, It's not just because corrosion of the fastener.
Movement of the manifolds would stress any fastener, plain carbon steel or stainless.
I'm surprised you have such detailed knowledge of fastener threads and fatigue resistance of materials with regard to exhaust bolts.
