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question on stainless bolts


reelcrzy
10-13-2009, 01:36 PM
Hello guys, I am in the process of putting my 2001 5.3 back together after replacing head gaskets and lifters. Someone told me i should replace the exhaust manifold bolts with stainless bolts. Is it ok to use stainless with alum heads ?? thanks

MT-2500
10-13-2009, 03:05 PM
I would just use regular grade 8 bolts with anti-seize.
Not sure how stainless steel bolts would take the heat.

And be sure to go new head bolts.
Good luck

reelcrzy
10-13-2009, 03:16 PM
Yes the heads are back on with new bolts. thx

MT-2500
10-13-2009, 03:59 PM
You are welcome.
New head bolts sounds good .
Good luck

wafrederick
10-13-2009, 09:07 PM
GM did upgrade the exhuast manifold bolts to a 13mm head since they had problem with the original bolts breaking off and the 6.0s are known for this.Also you have watch out on anything stainless steel,there is cheap and the best stainless steel.A magnet will stick to the cheap stainless steel

jdmccright
10-14-2009, 11:19 AM
Stainless steel that is magnetic is 400-series, usually 409 for exhaust components. As mentioned, it's okay, but cheaper and not as corrosion resistant or heat tolerant as the non-magnetic 300-series stainless steels. 304 and 316 are the most common for bolts but for very high temp applications, 321 and 347 are preferred. Higher quality bolts will have the alloy embossed right on the head.

Anything bolted into aluminum should have anti-seize applied unless not recommended by the head mfr.

reelcrzy
10-14-2009, 12:39 PM
The heads are the stock heads. Just had them resurfaced. I will use the anti-seize on the bolts. I orderd the bolts from fastenal not sure of the quality yet. thx

j cAT
10-14-2009, 08:46 PM
The heads are the stock heads. Just had them resurfaced. I will use the anti-seize on the bolts. I orderd the bolts from fastenal not sure of the quality yet. thx

do you have the torque sequence for the head fasteners...?
you go thru the M11 bolt fastening sequence first then you torque the M8 bolts...you must clean out the block thread locker from the M11 bolt holes/threads,,,the M11 bolts use the thread locker..


on the exhaust manifold bolts the first pass is 11ft lbs..the second pass is 18 ft lbs...with these bolts you also use thread locker...not antiseize...

also do not put the thread locker on the first three threads,,,and clean out all old thread locker before installing the fasteners..

unless the fasteners are designed for stainless steel the use of this material my cause these fasteners to get damaged to the point where removal would be impossible ,,,especially with aluminum metals.

reelcrzy
10-15-2009, 08:26 AM
I do have the sequence for the head bolts and they all came from gm with the orange dry threadlocker on them already. I will use locktite on the exhaust manifold bolts as well. thank you for the info.

j cAT
10-15-2009, 05:34 PM
I do have the sequence for the head bolts and they all came from gm with the orange dry threadlocker on them already. I will use locktite on the exhaust manifold bolts as well. thank you for the info.


thats great because as you can see this is quite detailed...

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