Copper or brass hardware for intake/exhaust manifold?

[Desertjr]

I've seen Jon (5-90) post on this before. I would like to get all new hardware for my header/intake vs the stock aged stuff. Jon if you see this what was your recommendation?

[SilverXJ]

These studs: http://www.mcmaster.com/#catalog/119/3150/=lr4vhj

And some self locking nuts or other locking method (not nylock)

http://www.naxja.org/forum/showthread.p ... 85&page=16 see post #303

[IH 392]

I'm on the third header and second intake (swapped to the '99 up) on my Jeep with 147K on it and never had any issue with the OE hard ware?, I did indeed torque it on every installation, some are hard to get to but it can be done. Do you just want shinny new parts??

[Desertjr]

These studs: http://www.mcmaster.com/#catalog/119/3150/=lr4vhj

And some self locking nuts or other locking method (not nylock)

http://www.naxja.org/forum/showthread.p ... 85&page=16 see post #303

Perfect thanks yet again silver

[SilverXJ]

I'm on the third header and second intake (swapped to the '99 up) on my Jeep with 147K on it and never had any issue with the OE hard ware?,

Same here.

[5-90]

I've seen Jon (5-90) post on this before. I would like to get all new hardware for my header/intake vs the stock aged stuff. Jon if you see this what was your recommendation?

Standard half hard naval brass works nicely for hex nuts.

For the screws, you need something a bit stronger - silicon bronze or aluminum bronze. Same properties otherwise apply.

For threadlocking, the best way to go is to:

(For screws) Round off a punch until the point is approximately ball-shaped. About 3-4 threads up from the tip, put the punch between thread crests - you may need a V-block. Fetch the punch ONE AND ONLY ONE whack - enough to deform the threads in that area. This will make the screw effectively self-locking (if you really want to, turn the screw 180* and repeat. This is "deformed thread locking" - most typically used with nuts, and it depends upon the plasticity of metal. Works neatly! However, it is recommended to replace deformed-thread self-locking fasteners with each removal.)

(For nuts) Round off a cold chisel on a grinder, that is wide enough to extend ALL THE WAY ACROSS the CORNERS of the next nut. Half-round shape again. Put the nut on a hard surface (cement, or steel bench block,) set the punch across corners, and give it ONE AND ONLY ONE whack with a mallet. The "undeformed" thread end goes on first. Replace on removal, as with screws.

If you examine OEM fasteners (like for suspension,) you'll usually see that a flanged nut has a mild triangular depression on the top surface - this is why. They're deforming the last thread, so it will "bite" against the exterior thread of the bolt/stud it's on, to make it bite.

It's not quite as effective as safety wire or castellated nuts, but it's actually a bit more effective than LocTite, and not sensitive to temperature. it may also be retorqued without needing to remove & reapply threadlocker.

I've been doing this for a bunch of years, and it's worked well for me!

[heavy equipment]

I installed Borla headers on two Cherokees using the original bolts/nuts/washers. Never a problem in several years. I chose Borla because of the 500,000 mile guarantee.
Exhaust manifold or header nuts may get hot enough to melt Loctite (600°).
3/8" capscrews or studs torque around 36 foot-pounds (better double-check that).
I use Never-seize on the threads, including threads deformed for locking. The lubrication gives more clamping force for the same amount of torque.

[SilverXJ]

I don't think there is any problem with the stock hardware. I've had my manifolds on and off several times using Thorley's torque specs (40ft lbs) and never had a problem with the bolts.

[heavy equipment]

I got Borla after the original manifold on my '89 cracked, I welded it, it cracked again, bought a new replacement manifold, it cracked... When I got my '90 Cherokee I got the Borla for it first thing! I attribute the cracking to long uphill pulls going 55 in second gear, combined with inadequate design of the manifold.

I don't know why Borla only recommends their header for a standard transmission, it fits fine with the AW4. I did add insulation between the pipes and the transmission and cooler lines.

[IH 392]

I use Never-seize on the threads, including threads deformed for locking. The lubrication gives more clamping force for the same amount of torque.

You have to be careful doing that, you can distort the hell out of the flanges before the torque is achieved and cause sealing issues!

[heavy equipment]

You have to be careful doing that, you can distort the hell out of the flanges before the torque is achieved and cause sealing issues!

A problem I've never had in 50+ years. If I'm not using Loctite I'm probably using Anti-Seize.

[SilverXJ]

Its not the head gasket which should be installed dry as well as the bolts. The stock torque i so low I don't think it would not matter on the manifold bolts.

[IH 392]

You have to be careful doing that, you can distort the hell out of the flanges before the torque is achieved and cause sealing issues!

A problem I've never had in 50+ years. If I'm not using Loctite I'm probably using Anti-Seize.

I've seen tons of distorted manifolds/headers, I've also seen bolts stretched out because they had antiseize on them and were over cranked down!
You must live in a rust belt if you gloop or glue everything together?

[heavy equipment]

I worked many years in an open pit Copper mine where equipment was used in acid solutions and wet conditions. I learned to deal with many different situations appropriately. Since I saw the same equipment over and over, I was able to find out what works and what doesn't. I became a big fan of stainless steel!