Exhaust Manifold Bolt Grades?

[pcmpete]

After removing my manifolds to clean them up and repaint them. The bolts that held on the manifold look a bit rusty and I am not 100% comfortable in using this bolts.
i went to my local hardware store and they had the following bolts:

1. Grade 5 Stainless Steel
2. Grade 8 non-stainless steel (gold color)

Which one of these bolts types would be best suited for this application?

 

[Lyle29464]

Re: Exhaust Manifold Bolt Grades?

stainless looks great but I have had them dissolve when used for exhaust manifolds. I know the steel will rust. No answer here. ;(

 

[ibrnrbr]

Re: Exhaust Manifold Bolt Grades?

the grade isnt going to matter for the application but the gold ones are prob galvanized which should be good to use. Im pretty sure thats what we ended up using on ours.

 

[rlbrooks99]

Re: Exhaust Manifold Bolt Grades?

You can't use stainless steel with the cast iron manifold, the two are not compatible and will corrode. And you only torque those bolts to 20 - 25 pounds so the grade is not a big factor either.

 

[OldNBold51]

Re: Exhaust Manifold Bolt Grades?

gold grade 8's.

 

[a70eliminator]

Re: Exhaust Manifold Bolt Grades?

The next owner will appreciate the grade 8's.

 

[a70eliminator]

Re: Exhaust Manifold Bolt Grades?

You can't use stainless steel with the cast iron manifold, the two are not compatible and will corrode. And you only torque those bolts to 20 - 25 pounds so the grade is not a big factor either.

I put my whole engine together with a stainless steel fastener kit, waterpump intake oil pan exhaust mainfolds everything, excecpt the head bolts and that was about 10 years ago and it still looks perdy today, grant you it's not a marine engine but cast iron nevertheless.