Got a cracked manifold, big suprise that an xj has that problem, huh? Anyways I'm going to order a new one from rockauto soon but they have two diffrent styles and was wondering which style has worked better for some of y'all. I'm really diggin the stainless header style one, but wonder if the one with the flex couplings on #1 and #6 cylinder will last longer and handle more flex. I attached links to both manifolds. Any input will be greatly appreicated.



http://www.rockauto.com/catalog/more...194&cc=1315943

http://www.rockauto.com/catalog/more...258&cc=1315943

 

The ATP styled one is quite a common upgrade, I have not heard of them cracking. I have heard of some slight clearance issues down by the collector but that is it. The shape and welds are different than stock to allow more efficient flow with less resistance.

The 2nd one is shaped just like the OEM but with the flex couplings to prevent the inevitable cracking problem the ones from the factory have.


tldr: buy what you can afford, both are good replacements that will not crack.

 

HEADER ASSEMBLY, 91-98 4.0L WRANGLER/CHEROKEE INCLUDES MANIFOLD GASKETS, POLISHED STAINLESS

 

Mine is similar to the ATP header, good for the money, just be careful to see whether or not the headers you order fit your year

 

APN header from ineedparts.com is a very common upgrade. I did it to mine and it's great for the money

 

The common cause of manifold cracks is a combination of the inherent rigidity of the XJ exhaust system, coupled with failing engine mounts (which allow increased relative motion between the engine and the body.)

Therefore, check your engine mounts as well - if one has failed, replace all three.

The single best fix would be to install a short flexible section just after the collector, between that flange and the forward catalytic converter flange. This would allow the engine to move relative to the chassis without straining the manifold, collector, or downpipe.

 

Is your header actually stainless? The description says stainless but the manifold in the pic is regular carbon steel. I like the price, but really want a stainless header. I have contacted ineedparts.com to confirm that it is stainless but they seem to be dragging their feet on the reply

 

Just ordered myself an ATP header, both motor mounts, and a valve cover gasket.

I liked the price of the APN header, but after finding out it wasnt really stainless. I figured it would be worth the extra $30 to get the stainless ATP. While inspecting my cracked manifold I noticed that my left motor mount is hard as a rock and starting to crumble. So I'm going to go ahead and replace the pair and the valve cover gasket while I'm there since it is starting to seep. Thanks for the help guys!

 

I've heard of these flex tubes/pipes like to rust out quick, any truth to this?

 

I've seen them used in some OEM applications, so I don't think they'd rust out too quickly... You should be able to locate it relatively high (just after the collector flange,) to maximise operating heat and keep water boiling off of it.

 

Just received my manifold Fri. and must say I'm dissapointed. This is the same manifold sold under the APN name and neither are stainless. Only diffrence is I paid more for my ATP because I thought it was stainless. After speaking with rockauto, they and the manufacture insist that it is stainless, But I still beg to differ. I'am a machinist with 15+ yrs exprience, and this my friends is NOT stainless. Oh well better luck next time I guess. I didnt expect much for less than $200 but I atleast expected it to be made from the material stated in the cat. description

 

I got a no name polished stainless one off eBay for $115. Also we t with brown dog motor mounts at the same time. All together I spent about $200. No more worries from that whole area.