Manifold torque specs

i know i've seen it on here but cant find it now when i need it so can someone post a link or give the torque specs and order for the intake/exhaust manifold bolts?

What year, what engine, is it an Iron or Aluminum Head?

I don't have the spec at the moment, just a note to remember all torques are dry torques unless otherwise noted. So if you use anti-seize, like a lot of people do, the lubrication will give you more crush or thread pull for a given amount of torque. I've seen suggestions like reduce spec torque by 15%-25% if you use anti-seize.

That is obviously more critical with aluminum, where spec torque is barely less than what will strip out threads in aluminum. Dealing with steel and cast iron, you probably would NOT have a problem.

Spark Plugs stripping out threads in aluminum heads is where it happens most, where lots of people use the anti-seize.

BTW, just for my own edification, didn't the later model 4.0L L6's have aluminum heads? Or do all of them have Iron Heads?

http://www.yuccaman.com/jeep/exhaust.html

http://www.universityofjeep.ca/borla_install.html

updated torque values, not sure what year this TSB is.

http://www.rebuiltautoengines.com/jeep-cherokee-articles.html

the lower bolts are a guess to torque, unless you have a chart to convert the torque values based on the the length of the extensions.
Rule of thumb: without accurate torque readings start loose and gradually torque in order until sealed, make sure the bolt threads are wire brushed cleaned and the head bolt holes are chased out, use a little antiseize, amen.

p.s. All production 4.0 litres were an iron head and block assy.

thanks alot, also does anyone know what bolts you need (how long, threads) and who would carry them?... and if anyone knows this stuff, how hard is replacing the motormounts too.

i know im getting off topic, will be doing this weekend and dont want to have to go to the store alot mid-job.

miketyson said:

thanks alot, also does anyone know what bolts you need (how long, threads) and who would carry them?... and if anyone knows this stuff, how hard is replacing the motormounts too.

i know im getting off topic, will be doing this weekend and dont want to have to go to the store alot mid-job.

Click to expand...

3/8"-16 x 1-1/4". Torque specs are also on my website.

You can use nonferrous screws for this application - I like using silicon bronze, but brass will also work - that makes them easier to remove next time. Use the same torque spec you would for ferrous/steel.

If all you can get are steel screws, use SAE Grade 5 - do not use SAE Grade 8! Grade 8 screws are harder than you'll need, but are also more sensitive to heat cycles, and will lose strength far more rapidly.

Be sure to re-use the "dish" shaped washers currently under the screw heads, they help to spread clamping loads.

The nuts on the OEM studs are 3/8"-24. You can make new studs (if you need to) from 3/8"-16 threaded rod - which you should be able to find locally. Get a foot of it, and cut off three 2-1/2" bits - one for each far end, one for the centre top. Get nuts to match, and get brass rod if it's available to you (same reason.)

If you want to use LocTite, use #272 or nothing else - no other grade can handle the heat. Do not use never-seez.

I just used LocTite #272 on my manifold bolts, I was worried that the red color meant it would be difficult to disassemble. It wasn't, I just it apart again (still had a problem with one of the studs on the end) and the LocTite #272 is no more resistance than Blue "Medium" Loctite. I didn't even heat cycle it, so the #272 Hi-Temp Loctite is the trick in my book.

there are 11 bolts attatching the manifold and 2 nuts at the downpipe that i should repalce right? where are the studs and do they need to be replaced?

9 bolts, and 2 studs fasten the manifolds. The block studs are removable, but I'm not sure how you safely turn them out.

The exhaust manifold to header pipe flange has a pair of splined studs that can be driven out with a hammer.

Why replace the all the manifold hardware?

I'm trying to find a bolt kit for doing my manifold swap. I found this one through Parts America, but it only has 7 bolts and 2 studs. Anyone know a btter place to get a kit from?
http://www.partsamerica.com/ProductDetail.aspx?MfrCode=DOR&MfrPartNumber=03408&PartType=725&PTSet=A

3 places i've seen stocking a manifold bolt pack
oddly, this pack has two additional studs, 4 total. that's only 9 fasteners again.
Maybe those two end studs are permanant residents.

http://www.jeepparts.cc/catalog/?section=632

Jeep Manifold Attaching Package
List Price $36.00
Our Price $34.29
Package of factory original nuts and bolts to attach intake manifold and exhaust manifolds. Includes five bolts, seven washers, four studs, two pins, two spacers and three plugs for Jeep engines.

same below

http://www.southeastperformance.com/mopar-catalog.php?cat=9&item=601
Package of factory original nuts and bolts to attach intake manifold and exhaust manifolds. Includes five bolts, seven washers, four studs, two pins, two spacers, and three plugs for Jeep engines.

http://www.bpemopar.com/DODGE_TRUCK_MAGNUM_JEEP_ENGINES.htm

E. Intake Manifold Attaching Package
Package of factory original nuts and bolts to attach intake manifold and exhaust manifolds. Includes 5 bolts, 7 washers, 4 studs, 2 pins, 2 spacers, and 3 plugs for Jeep engines.
P4529680 Intake Manifold Attaching Package (1987–89 4.0L Jeep Engines)

92DripCherokee said:

3 places i've seen stocking a manifold bolt pack
oddly, this pack has two additional studs, 4 total. that's only 9 fasteners again.
Maybe those two end studs are permanant residents.

Click to expand...

That's what is confusing me. The write up below mentions 9 bolts and 2 studs:
http://www.naxja.org/forum/showpost.php?p=880386&postcount=2

You can also tell from his pictures that it is 9 bolts, 2 studs, and 2 alignment rods.