Exhaust Manifold Bolts
#11
03-03-2012, 01:49 AM
Professional
Join Date: Oct 2010
Location: Big Rapids, MI
Posts: 174
Likes: 0
Received 0 Likes
on
0 Posts
i bought steel bolts for my manifolds before i discovered home depot sold stainless steel bolts. if you plan on keeping the truck stainless steel bolts might be worth the extra money. i think eventually i would like to get stainless steel bolts so they won't rust up and be a pain to remove. i hate when the heads practically rust off like this.
#12
03-03-2012, 03:13 PM
Champion
Where's the leak? cracked header or just bad gasket?... I recently had one of my pacesetters crack and bought some stainless headers from a seller called "Eworldsales1"... I did a did by side comparison of the pacesetters next to the stainless ones (with pics posted) https://dodgeforum.com/forum/2nd-gen...mparision.html
The stainless ones seem to be better in every way.. all the stuff I heard about bolt clearances and bad welds and having to clearance the flanges for spark plug holes must be from a different headers manufactuer sold on ebay because they are exact replicas as far as bends and design as the pacesetters only better material and better quality welds...flanges are the exact same size and cut identical only thicker and they even come with felpro gaskets and stainless bolts (though I recommend better grade 8 stainless bolts)
I did some deep looking and thier are at least two different types of ebay no name headers.
A great deal for $148 shipped I think...
The stainless ones seem to be better in every way.. all the stuff I heard about bolt clearances and bad welds and having to clearance the flanges for spark plug holes must be from a different headers manufactuer sold on ebay because they are exact replicas as far as bends and design as the pacesetters only better material and better quality welds...flanges are the exact same size and cut identical only thicker and they even come with felpro gaskets and stainless bolts (though I recommend better grade 8 stainless bolts)
I did some deep looking and thier are at least two different types of ebay no name headers.
A great deal for $148 shipped I think...
Last edited by Augiedoggy; 03-03-2012 at 03:19 PM.
#13
03-03-2012, 07:02 PM
Professional
Join Date: Nov 2011
Location: Canada
Posts: 189
Likes: 0
Received 0 Likes
on
0 Posts
Just be careful when subbing SS fasteners for steel ones. It would be best if you could find out the grade of the bolt used in the OEM exhaust. A good photo of the head of the OEM bolt should be enough.
"Hardware Store" SS bolts can be weaker than the steel bolts they replace because many decorative grade SS bolts are not made from an alloy recommended for structural use. So, see if you can determine the grade of the fastener you're buying. Also, generally speaking SS bolts cannot be made as strongly as steel bolts.
Weakest to Strongest:
[For bolts 1/4" to 1"]
Low grade steel; anything below Grade 5, marked 307A, 307B, not marked; ... no yield rating, 60,000 psi tensile [you can freely sub SS for these fasteners]
[all diameters]
SS 300 series 18/8 ... 2 bars on head; ... 30,000 yield 70,000 tensile [Typical Hardware Store variety]
SS Various other grades SS marked: B8, B8M, B8A, B8MA, B8C, B8T; ... 30,000 yield 75,000 tensile
SS Nitronic 60 Solution Treated marked B8S; ... 50,000 yield, 90,000 tensile
SS Nitronic 50 Solution Treated marked B8R; ... 55,000 yield, 110,000 tensile
[1/4 to 4"]
SS 410 Stainless Quenched + Tempered, marked B6; ... 85,000 yield, 110,000 tensile
[1/4 to 1"]
Grade 5 Steel ... 3 bars on head; ... 85,000 yield 120,000 tensile
[1/4 to 1 1/2"]
SS Annealed, Age Hardened, marked F93U; ... 105,000 yield, 135,000 tensile [the strongest SS bolt available]
[1/4 to 1 1/2"]
Grade 8 Steel ... 6 bars on head; ... 120,000 yield, 150,000 tensile
Also, BE SURE to use anti-seize on any SS fastener going into iron, aluminum, mild steels, and it's recommended even if going into another SS part since the composition might be different between the fastener and the item the bolt threads into. Use a torque wrench when tightening SS bolts because over-torquing will cause bolt failure. Also be sure the torque values required for assembly don't exceed the strength of the SS bolt ... you don't want a SS bolt with no head stuck in anything, period.
WE have a place in town that sells only bolts and fasteners (The Bolt Supply House) so getting fasteners is never a problem for me. They have everything you might want, usually in stock, including rare grades and sizes. I find the selection at Home Hardware weak, but that could just be the stores around here.
I used to use SS bolts too for various dress-up engine and vehicle uses, but I've had problems with them. These days if I need appearance I use the steel bolts and paint unless it's a low-strength assembly.
However if you can find B6 SS they are a good fastener for substitution up to grade 5 steel. Those are the bolts I would try to use for headers, with anti-seize. They are not as corrosion-resistant as the 300 (B8) grades, but they clean up well enough. Use a torque wrench and don't torque to final value (get close, maybe 85%) until after you've run the engine a while, then re-torque to final. SS bolts don't stretch like steel does.
A good alternative method of attaching headers that have heat/cooling cycles that tend to loosen bolts is to use an extra-long bolt with a good quality nut. Tighten the bolt down until it's firmly seated in the head, then tighten the nut to bring the header itself tight. It is not necessary to torque the bolt fully with this method. You then will be able to tighten the header at any time by holding the bolt head with a wrench and tightening the nut alone.
This stretches the part of the bolt between the header and the head, giving some elastic strength that helps handle the heat cycling, yet doesn't require torquing the bolt very hard. It works very well with soft threaded heads, like aluminum. By backing off the nut slightly you will almost always be able to then back off the head and remove the bolt. If it does break, there is often enough meat there to make removal easier, although it's rare to break a bolt this way.
In aircraft they often use two nuts, one thinner called a "jam nut". This second jam nut is tightened once the first nut is fully seated, acting as a very high strength lock washer. You have to loosen the jam nut first, then the holding nut, to remove the bolt. It works well in high vibration assemblies, or when frequent removal is necessary.
"Hardware Store" SS bolts can be weaker than the steel bolts they replace because many decorative grade SS bolts are not made from an alloy recommended for structural use. So, see if you can determine the grade of the fastener you're buying. Also, generally speaking SS bolts cannot be made as strongly as steel bolts.
Weakest to Strongest:
[For bolts 1/4" to 1"]
Low grade steel; anything below Grade 5, marked 307A, 307B, not marked; ... no yield rating, 60,000 psi tensile [you can freely sub SS for these fasteners]
[all diameters]
SS 300 series 18/8 ... 2 bars on head; ... 30,000 yield 70,000 tensile [Typical Hardware Store variety]
SS Various other grades SS marked: B8, B8M, B8A, B8MA, B8C, B8T; ... 30,000 yield 75,000 tensile
SS Nitronic 60 Solution Treated marked B8S; ... 50,000 yield, 90,000 tensile
SS Nitronic 50 Solution Treated marked B8R; ... 55,000 yield, 110,000 tensile
[1/4 to 4"]
SS 410 Stainless Quenched + Tempered, marked B6; ... 85,000 yield, 110,000 tensile
[1/4 to 1"]
Grade 5 Steel ... 3 bars on head; ... 85,000 yield 120,000 tensile
[1/4 to 1 1/2"]
SS Annealed, Age Hardened, marked F93U; ... 105,000 yield, 135,000 tensile [the strongest SS bolt available]
[1/4 to 1 1/2"]
Grade 8 Steel ... 6 bars on head; ... 120,000 yield, 150,000 tensile
Also, BE SURE to use anti-seize on any SS fastener going into iron, aluminum, mild steels, and it's recommended even if going into another SS part since the composition might be different between the fastener and the item the bolt threads into. Use a torque wrench when tightening SS bolts because over-torquing will cause bolt failure. Also be sure the torque values required for assembly don't exceed the strength of the SS bolt ... you don't want a SS bolt with no head stuck in anything, period.
WE have a place in town that sells only bolts and fasteners (The Bolt Supply House) so getting fasteners is never a problem for me. They have everything you might want, usually in stock, including rare grades and sizes. I find the selection at Home Hardware weak, but that could just be the stores around here.
I used to use SS bolts too for various dress-up engine and vehicle uses, but I've had problems with them. These days if I need appearance I use the steel bolts and paint unless it's a low-strength assembly.
However if you can find B6 SS they are a good fastener for substitution up to grade 5 steel. Those are the bolts I would try to use for headers, with anti-seize. They are not as corrosion-resistant as the 300 (B8) grades, but they clean up well enough. Use a torque wrench and don't torque to final value (get close, maybe 85%) until after you've run the engine a while, then re-torque to final. SS bolts don't stretch like steel does.
A good alternative method of attaching headers that have heat/cooling cycles that tend to loosen bolts is to use an extra-long bolt with a good quality nut. Tighten the bolt down until it's firmly seated in the head, then tighten the nut to bring the header itself tight. It is not necessary to torque the bolt fully with this method. You then will be able to tighten the header at any time by holding the bolt head with a wrench and tightening the nut alone.
This stretches the part of the bolt between the header and the head, giving some elastic strength that helps handle the heat cycling, yet doesn't require torquing the bolt very hard. It works very well with soft threaded heads, like aluminum. By backing off the nut slightly you will almost always be able to then back off the head and remove the bolt. If it does break, there is often enough meat there to make removal easier, although it's rare to break a bolt this way.
In aircraft they often use two nuts, one thinner called a "jam nut". This second jam nut is tightened once the first nut is fully seated, acting as a very high strength lock washer. You have to loosen the jam nut first, then the holding nut, to remove the bolt. It works well in high vibration assemblies, or when frequent removal is necessary.
Last edited by Johnny2Bad; 03-03-2012 at 08:36 PM.
#14
03-03-2012, 07:56 PM
Legend
i don't mind bolts that are decorative. my manifolds fit my 318 so perfect that i don't even have a gasket installed. just need something to hold the manifolds.
i think home depot has a bit better selection of bolts than home hardware. my local home hardware does not carry SS fastener but they do have a very good selection of key. there is also a brafasco but there is a minimum $10 limit.
i think home depot has a bit better selection of bolts than home hardware. my local home hardware does not carry SS fastener but they do have a very good selection of key. there is also a brafasco but there is a minimum $10 limit.
#15
03-03-2012, 08:41 PM
Professional
Join Date: Nov 2011
Location: Canada
Posts: 189
Likes: 0
Received 0 Likes
on
0 Posts
i don't mind bolts that are decorative. my manifolds fit my 318 so perfect that i don't even have a gasket installed. just need something to hold the manifolds.
i think home depot has a bit better selection of bolts than home hardware. my local home hardware does not carry SS fastener but they do have a very good selection of key. there is also a brafasco but there is a minimum $10 limit.
i think home depot has a bit better selection of bolts than home hardware. my local home hardware does not carry SS fastener but they do have a very good selection of key. there is also a brafasco but there is a minimum $10 limit.
Good tips for installing SS fasteners here:
http://www.estainlesssteel.com/gallingofstainless.html
Looks like the exhaust bolts are 5/16-18 all you need is correct length. Headers mount with 1". From the picture a guess would be 2" with a 1" shoulder but you should find out the exact dimensions.
Last edited by Johnny2Bad; 03-04-2012 at 04:45 AM.