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post #1 of (permalink) Old 01-23-2003, 07:00 PM
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Warped exhaust manifold

I have been buttoning up my 2.5 4 cylinder in my 86 XJ.
I haven't had a problem until we started bolting on the
intake and exhaust manifold, the exaust manifold seemed to have, warped in the middle and pulled the bolt holes away from the head blot holes where they should be. I noticed an exhaust leak in the center of the manifold, the burns on the engine block paint, I put on earlier. Has any body ever had this problem, it is a cast iron stock manifold. I noticed a set of stainless steel headers from Rubicon Express.com They cost $179.99. Is stainless a good option, I have the money for at the most 200.00 bucks, love to stay away from that if possible, I want a little more flow, than my stock manifold. Please help me. Thanks [img]images/graemlins/confused.gif[/img]
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post #2 of (permalink) Old 01-24-2003, 01:48 PM
Way Outta Control
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Re: Warped exhaust manifold

1. Cast Iron manifolds warp, it's just a fact of life.
2. You've got a few choices...
a. Take it to a machinest and have it faced and trued.
b. Buy a new/used cast iron manifold.
c. Buy an aftermarket manifold.
d. Buy "spreaders" to align the runners on re-install.
3. Me, I'd buy the spreaders,
4. You can't have too many tools!
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post #3 of (permalink) Old 01-24-2003, 09:27 PM
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Re: Warped exhaust manifold

If you see visual warpage I'd almost go for the machinist facing. The spacers might cause more leaks later on, but they do work. And you know when they go bad b/c it gets loud. But anything's on the list is cheaper than $190!
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post #4 of (permalink) Old 01-25-2003, 12:44 AM
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Re: Warped exhaust manifold

First, before you blame the entire problem on the manifold, put a strait-edge on the block, if you are true there, take the manifold to the local NAPA Machine shop. They'll have it trued and shaved in no time....About $30 bucks....also, remember, not all gaskets are created equal. I like Mr Gasket's stuff, but you may want to use double gaskets or those thin copper ones. If it were me to do over again, I'd have wrapped my exaust manifolds in temp wrap, as the intake/exaust manifolds are so close together. My buddie did it and swears that the difference was noticed in HP and milage, especially in the summer. This forces the heat down the pipe to the catalitic converter (if still equipped) and helps emissions and the flow of the exaust as well as cooling down the intake's overall temp. For power, ultimately a header is the way to go. You really do lose HP pushing the old exaust out of the way, but headers are thin (read: loud) and expensive. The Cast iron manifold is quieter, but if you're running that dinkey 2.5, you might be looking for any extra little advantage. By going to the header you save BOTH on the weight and the added flow. Your choice...... [img]images/graemlins/burnout.gif[/img]
post #5 of (permalink) Old 01-25-2003, 07:09 AM
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Re: Warped exhaust manifold

I like headers [img]images/graemlins/smile.gif[/img]. Put a set of Edelbrock headers on my 85 XJ back in 87. Beleive it or not I am still running the same set [img]images/graemlins/shocked.gif[/img] (and they're not stainless)!! Noticed an increase in gas mileage and performance. Not that it is a tire smoker or anything, but it's peppier then it was.
The exhaust manifold on my 83 CJ7 warped and I replaced that with a Borla stainless steel header. Again, I noticed an increase in gas mileage and performance. It is only louder then the stock manifold when I mash on it; but when I do, it sounds GREAT!!! [img]images/graemlins/burnout.gif[/img]
As for the exhaust wrap, I've heard pros and cons. Above was mentioned a pro. Now a con: I've heard exhaust wrap traps moisture which will eventually bring about rust and deterioration.
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