Exhaust manifold bolts

[Hagar1]

Another downside to S/S bolts, they won't stretch at all and will just snap. At least the steel ones will stretch a bit.

Just running through my mental notes and I recall following the prescribed torque sequence and values except I stayed slightly under prescribed torque on the rear bolts because they get the most heat therefore would need to stretch the most.

 

[Bob Horowski]

Depending on what grade of stainless steel bolts you use will determine the amount of stretch that will occur before snapping. ALL stainless steel bolts stretch before failing completely.

 

[Wild one]

I'd use a cheap Grade 5 style bolt,you're only torquing the manifolds to 20 lb-ft at most,and the last thing you want is a bolt that pulls the threads in the aluminium head and doesn't break.Cheaper bolts of a lower grade number usually have a better stretch factor before they break

 

[17ramandy]

Depending on what grade of stainless steel bolts you use will determine the amount of stretch that will occur before snapping. ALL stainless steel bolts stretch before failing completely.

Do you have suggestions for the right stainless bolts/studs to use?

 

[mikeru]

Do you have suggestions for the right stainless bolts/studs to use?

As I mentioned in post #35, stainless steel and aluminum do not play well together. Galvanic corrosion can occur between the two. I would advise against using stainless steel bolts for this.

 

[Ken226]

I agree with Mikeru. If they break again in the future, I want them to be easy to remove. Avoid the possibility of galvanic corrosion.



i'd take "uniform surface rusting" any day over "more aggressive, rapid, localized pitting".




Also, like WildOne mentioned above. If the manifolds warp until something gives, i'd prefer it be the bolts that break. Anything else involved that breaks would cost more than the bolts to replace.

I've done 4 Hemis with the Dorman bolts from Amazon. In my opinion, that you re-surface the old, warped manifolds before reinstalling is more important than which fasteners or gaskets you use.


But, for those who want to use the Remflex gaskets, The bolts only, per side:

https://a.co/d/0g4SrZIB

Kit form, for both sides including gaskets. This is what I used in mine back in 2024, and the wifes Durango back in 2019:

https://a.co/d/0bwGr4IT

 

[17ramandy]

As I mentioned in post #35, stainless steel and aluminum do not play well together. Galvanic corrosion can occur between the two. I would advise against using stainless steel bolts for this.

Yes, I saw your post but @Bob Horowski seemed to have some additional information and coming from a marine background I was just wondering..

 

[17ramandy]

I agree with Mikeru. If they break again in the future, I want them to be easy to remove. Avoid the possibility of galvanic corrosion.

View attachment 583662

i'd take "uniform surface rusting" any day over "more aggressive, rapid, localized pitting".




Also, like WildOne mentioned above. If the manifolds warp until something gives, i'd prefer it be the bolts that break. Anything else involved that breaks would cost more than the bolts to replace.

I've done 4 Hemis with the Dorman bolts from Amazon. In my opinion, that you re-surface the old, warped manifolds before reinstalling is more important than which fasteners or gaskets you use.


But, for those who want to use the Remflex gaskets, The bolts only, per side:

https://a.co/d/0g4SrZIB

Kit form, for both sides including gaskets. This is what I used in mine back in 2024, and the wifes Durango back in 2019:

https://a.co/d/0bwGr4IT

This is perfect, thanks!

 

[Ken226]

This is perfect, thanks!

No prob.

The most important part of making sure the problem doesn't recur, is resurfacing the gasket mating face of the old, heat cycled manifolds. If you are replacing them with new manifolds, you'll probably be doing it again in 50,000 miles.
And yea, i've even heard of a recent case of new BD Diesel manifolds warping. Even the heavy duty, reenforced ones aren't immune from the laws of physics:

BD Diesel manifolds for 5.7

Of course my 5.7 had the broken bolt issue I put BBK shorty headers on it supposed to fix the problem, it did for a year until the wields opened a good size hole. Did my research and BD Diesel manifolds says they have solved all the problems the original manifolds had. So I had the dealer...

www.ramforum.com

The Harbor Freight 6x48 belt sander is perfect for the job. You can buy the belt sander for $250 and the bolt/gasket kit for $80, and be into the whole thing for 330$. Then, you'll still have the belt sander for future projects.



Less than half what a shop would charge you, or as per a recent post on the forum, 1/15th of what the dealer would charge. https://www.ramforum.com/threads/manufacturing-defect-should-be-taken-care-of-by-ram.224901/

When I do it, i like to put a light, mist coat of bright colored krylon on the face before sanding. So it's easy to see when I have it flat.

 

[Slinge]

When using Remflex gaskets , are longer bolts required ?
If so are longer bolts made to accommodate the OEM heat shield . ?