Manifold Installation

[HeavyDuty204]

Had an exhaust leak at the passenger side manifold, got new gaskets and the mating face of the manifold machined.

What are the torque specs for the man - head and man to up-pipe? Also after torquing do I just run the truck up to operating temp and retorque?

 

[WVRigrat05]

35 ft/lbs, and I never re-torqued, but I guess it couldn't hurt.

 

[Hot COCOAL]

It's actually 42ft lbs...
http://www.socaldiesel.com/LBZ Torque Specs.htm

I get them all finger tight first...
Tighten them starting from the center of the manifold out doing both upper and lower bolts then move forward and aft...
It never hurts to recheck the bolts after a few heat cycles...

 

[HeavyDuty204]

Thanks guys, torqued em to 35 lbs...

Read that lb7 & lly are 28 lbs and lbz's are 42 lbs. So not sure what lmm's and Lml's are but I'll drive er and see if they need torquing.

 

[dirty_max]

Thanks guys, torqued em to 35 lbs...

Read that lb7 & lly are 28 lbs and lbz's are 42 lbs. So not sure what lmm's and Lml's are but I'll drive er and see if they need torquing.

lmm and lbz are pretty much the same. i would venture out to guess that the lml is closer to the lmm than the lb7 or lly though.

 

[c20elephant]

I replaced both my manifolds and had to remember these heads are aluminum and not much torque would be needed to pull the threads out if over tightened

 

[BHoward6.6]

I replaced both my manifolds and had to remember these heads are aluminum and not much torque would be needed to pull the treads out if over tightened

Ah yes, the benefit of a high quality torque wrench.

 

[OregonDMAX]

I got a pretty good right arm torque wrench.

 

[Hot COCOAL]

My bigger concern would be making sure the torque was even between all the bolts...

I would "think" that if you didn't get them all close to the same tq yield it would be possible to eventually heat cycle the manifolds out of square/flatness and possibly run into sealing issues down the road...

I'm not saying it's likely or probable, but I would think that it would be possible...

 

[OregonDMAX]

Turning wrenches for a living for many years I got a feel for what is right.

I have a torque wrench but I only use it on motor or tranny internal parts where torque is key to optimum life and reliability.

 

[WVRigrat05]

Turning wrenches for a living for many years I got a feel for what is right.

I have a torque wrench but I only use it on motor or tranny internal parts where torque is key to optimum life and reliability.

I haven't turned wrenches for years but I do the same thing, I did torque my intake runners and manifolds but I still stripped a couple of stupid bolts out with a calibrated snap on wrench so all the low torque stuff I do by hand.

 

[HeavyDuty204]

So far so good, it's a tight squeeze while getting the bottom bolts tq'd up...

I'll run a few more heat cycles and check again