Torque Specs
Thread Starter
Burning Brakes
Joined: Jun 2012
Posts: 1,240
Likes: 1
From: Orange County California
Torque Specs
Does anyone know the Torque soecs for the exhaust manifold studs that bolt the manifold to the cylinder head....I broke one and had to use an easy out to remove it...and don't want to repeat that, but I have a slightly warped header surface and need to be able to tighten it enough to close the minor exhaust leak.
Thsnks in advance guys
Thsnks in advance guys
Tech Contributor
Joined: May 2008
Posts: 3,100
Likes: 17
From: Somers, CT and Clermont, FL
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16
The torque specs from the 2001 FSM's are: 11 lb ft on the first pass, and 18 lb ft on the final pass.
Begin at the center bolts, and alternately tighten the bolts from the center outward.
Rather than over tightening the bolts to close the warped header flange surface, try using two manifold gaskets instead. It will usually do the trick if the warpage is not too excessive.
Begin at the center bolts, and alternately tighten the bolts from the center outward.
Rather than over tightening the bolts to close the warped header flange surface, try using two manifold gaskets instead. It will usually do the trick if the warpage is not too excessive.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
The bolt TORQUE is determined by the bolt material, thread pitch and how much it takes to apply the correct clamping force to the fastener to achieve the correct bolt stretch AND what determined the bolt screws into. I.E. Aluminum
Clamping a cast iron manifold or a SS Header flange shouldn’t make any difference. It still 11 first pass/ 18 finial pass.
Clamping a cast iron manifold or a SS Header flange shouldn’t make any difference. It still 11 first pass/ 18 finial pass.
Le Mans Master
Joined: Mar 2011
Posts: 6,835
Likes: 301
From: Columbia SC
It is normal to select the torque based on the gasket design/material in this situation since the head material is the same and the header material is equivalent. You can call LG and confirm.
PS: Using 2 OEM style gaskets (if you have some warpage) should not really affect the torque you use in my opinion.
Did not see Bill's comment until I posted, but also agree with his input.
PS: Using 2 OEM style gaskets (if you have some warpage) should not really affect the torque you use in my opinion.
Did not see Bill's comment until I posted, but also agree with his input.
Last edited by dadaroo; Mar 5, 2013 at 11:43 AM. Reason: Add comment
Tech Contributor
Joined: May 2008
Posts: 3,100
Likes: 17
From: Somers, CT and Clermont, FL
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16
You might lose a thread or two of bolt engagement, due to the extra gasket thickness, but the extra gasket itself should have little effect on the final clamping force at the specified torque value.
I would probably use studs and nuts, instead of bolts, to allow the full thread engagement with the extra gasket thickness.
Thread Starter
Burning Brakes
Joined: Jun 2012
Posts: 1,240
Likes: 1
From: Orange County California
Actually its my LT's that got slightly heat warped ;-)
the dealership and part stores look up the part as "exhaust manifold" bolts though, so I just used that here.
header bolts and exhaust manifold bolts are the same thing
and thanks for the compliments!
Thread Starter
Burning Brakes
Joined: Jun 2012
Posts: 1,240
Likes: 1
From: Orange County California
thanks everyone...The parts store near me only had one set of Felpro gaskets...Out of expedience I ended up using the stock metal gaskets on the side toward the manifold (LT headers), and the felpro gasket on the side towards to heads....I also tightened from the center outward, and very gently went to about 24 FPT on the second pass on the center bolts...after two days of driving no more leaks so far.
The two gasket solution, and tightening from the center bolts outward seems to have done the trick, after another week of spirited driving I'll know for sure, but for now its holding up.
Note to self, (and everyone else): Tighten the header flanges to the heads from the center outward ;-)
The two gasket solution, and tightening from the center bolts outward seems to have done the trick, after another week of spirited driving I'll know for sure, but for now its holding up.
Note to self, (and everyone else): Tighten the header flanges to the heads from the center outward ;-)
Last edited by steven31371; Mar 6, 2013 at 11:09 AM.
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Thread Starter
Burning Brakes
Joined: Jun 2012
Posts: 1,240
Likes: 1
From: Orange County California
You might lose a thread or two of bolt engagement, due to the extra gasket thickness, but the extra gasket itself should have little effect on the final clamping force at the specified torque value.
I would probably use studs and nuts, instead of bolts, to allow the full thread engagement with the extra gasket thickness.
Tech Contributor
Joined: May 2008
Posts: 3,100
Likes: 17
From: Somers, CT and Clermont, FL
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16
Thread Starter
Burning Brakes
Joined: Jun 2012
Posts: 1,240
Likes: 1
From: Orange County California
yep
needed a benchmark to have an idea of how tight I could go without breaking the bolt again...had to go over a bit because even with two gaskets there was still a tiny leak.
All good now.
Tech Contributor
Joined: May 2008
Posts: 3,100
Likes: 17
From: Somers, CT and Clermont, FL
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16
I'm glad you got it fixed.
