AMC Eagle Den Forum

The Mighty 258 => Exhaust System. => Topic started by: GoldenEagle258 on June 24, 2012, 11:33:05 PM

Title: 258 warped exhaust manifold
Post by: GoldenEagle258 on June 24, 2012, 11:33:05 PM
So my exhaust manifold is warped and im looking into building an exhaust for the eagle while i change it out.
Do Clifford or Renix manifolds really flow better than stock? are they worth it?
Im still debating what muffler to get but i think im going to ditch the cat and have a side out exhaust.
Any info or advice is appreciated.
Title: Re: 258 warped exhaust manifold
Post by: GoldenEagle258 on January 14, 2013, 02:46:59 PM
anyone?
Title: Re: 258 warped exhaust manifold
Post by: carnuck on January 14, 2013, 03:14:04 PM
Clifford might not fit right someone was saying. I'm modding an HO for my Eagle IF I can finish it.
Title: Re: 258 warped exhaust manifold
Post by: greymarooneightytwo on January 14, 2013, 03:18:56 PM
I've heard rumors that one of the "high flow true dual" headers (split manifolds, as true as it gets without a "V") on the market for the 258 will fit, but I'm not sure which one it was.

That being said, I can tell you for certain that it's a very tight squeeze as as is, there's not much room with the crossmember and front diff right there...

Also keep in mind most places in the US, even emissions free places, require exhaust to extend "beyond the cab"... so in a truck, side exhaust is fine, but with sedans and wagons it must go all the way back.

I'm also redoing my exhaust right now though, so let me know if you find a header that will fit.

I went with a flowmaster 40 (vanilla, not super or delta) single in dual output.

I saw this video and liked the sound of it:

http://www.youtube.com/watch?v=PJasB7typfw (http://www.youtube.com/watch?v=PJasB7typfw)

He's running the single header, to a flowmaster 40 single in/out, with a "y" pipe, but I decided I wanted the outs to be the same length, and if I want to mount it where the old muffler went, I might as well just have them protrude side by side instead of opposite sides of the gas tank.

I'll post some pictures when it's all done.

As for the headers, here's some more discussion on the topic:

http://forums.amceaglenest.com/index.php?topic=38616.15 (http://forums.amceaglenest.com/index.php?topic=38616.15)
Title: Re: 258 warped exhaust manifold
Post by: GoldenEagle258 on January 15, 2013, 12:22:10 PM
thanks for the replies carnuck and gm82.

that vid of the flowmaster 40 sounds amazing, i was actually looking toward flowmaster for my can. ill prob end up doing single output though. im not too worried about the side out, no one really cares in wyoming.

so it looks like clifford and oe are the only 2 options without having to worry about modifying the headers to fit. thanks, thats exactly what i was hoping to find out.

BUT, i just got off the phone with larry at clifford and due to lack of demand he hasnt made the headers in a while and they are currently out of stock. if anyone is interested, we could get a group buy going and he would make some if there is the demand...anyone in?
Title: Re: 258 warped exhaust manifold
Post by: eaglebeek on January 15, 2013, 12:39:49 PM
GoldenEagle, I'm getting the feeling you want to go with an aftermarket/4.0 exhaust manifold...but regarding your warped stock manifold...how much is it warped? I'm wondering if a machine shop with a milling machine can economically restore the mating surfaces of your stock manifold.

Title: Re: 258 warped exhaust manifold
Post by: eagleman on January 15, 2013, 02:33:18 PM
When I removed my stock exhaust manifold  to replace the two busted exhaust studs. Both of the end ones I found my manifold to be warped also. I took it to a local machine shop that does diesel and heavy equipment engine rebuilds and he checked it and gave it a surface job. Got it back and it was nice and flat. Charged me twenty bucks which I thought was reasonable.
Title: Re: 258 warped exhaust manifold
Post by: twoslowinwyo on January 15, 2013, 08:13:34 PM
any good automotive machine shop will be able to fix it for you. i would be more concerned on why it warped? was a bolt loose or missing? if it's not too bad, and you could find a belt sander big enough you might be able to clean it up enough to work. i have done 4-cyl. manifolds with this method and never a 6-cyl. it sounds medevil redneck but it worked. best of luck. LAZ
Title: Re: 258 warped exhaust manifold
Post by: BenM on January 16, 2013, 11:15:03 AM
There's a set of 258 headers out there that fit the Eagle. If you search back through the forum you'll probably find it. I think it works best with the aluminum intake.

Personally, I wouldn't expect much with the 258 head on it. The cast iron exhaust manifold was redesigned with the aluminum intake to be more free-flowing then the old bolt-together set, but I wouldn't know how much that matters, probably more with an aftermarket carb.

The '81 ought to be the earlier bolt-together cast iron set.

Even if they're not broken, get some fresh studs and replace the end ones, you may want to go a hair longer to make threading easier. I may have put a few in other hard-to-reach areas, I can't remember.

Title: Re: 258 warped exhaust manifold
Post by: kajsdf on January 18, 2013, 03:37:19 PM
i'm confused -- i see mentions of 4.0 and 258 manifolds/headers in this thread...4.0 headers have fitment issues if i remember right, and clifford's 258 long tube header designed for eagles is fantastic.  i had to bend mine slightly (it was just a hair too close to the driveshaft) which is easily done with a long pry bar after letting it run through a few heat cycles to allow the metal to flex.  they flow tons better and if you are going to do any building to the internals of your motor i strongly recommend it.  it's priced kinda high but compared to the cost of other high-quality headers it's quite reasonable.  you may have to call/email them about it because it was not listed on the site when i ordered mine.  i do not know about clifford's dual headers but they state they fit 'amc passenger cars' -- ie eagle, concord, etc but i have a feeling routing some exhaust will be interesting for those.
Title: Re: 258 warped exhaust manifold
Post by: priya on January 19, 2013, 11:47:30 AM
i do not know about clifford's dual headers but they state they fit 'amc passenger cars' -- ie eagle, concord, etc but i have a feeling routing some exhaust will be interesting for those.

The dual headers won't fit without a great deal of modification, one of the collectors comes down right on top of the front differential.  Another Eagle nest member sent me this picture, asking why my Clifford header fit and his didn't - I have the single outlet header.
(http://i276.photobucket.com/albums/kk14/priyalynn/photo.jpg)
Title: Re: 258 warped exhaust manifold
Post by: Will on February 05, 2013, 06:27:31 PM
im still stuck with the stock header at the moment.  just got off the phone with the lady who works for clifford.  she told me that they didn't make a single outlet header.  WHAT???!!! Can you send me a pic of your headers Priya?.  Specifically how it runs out of the engine bay?

Best,

Will
Title: Re: 258 warped exhaust manifold
Post by: carnuck on February 08, 2013, 01:31:57 AM
I have a Renix, an HO and the replacement accordion exhaust I will test fit in my Eagle while I have the AIR emission piped one removed to put in a non-AIR manifold.
Title: Re: 258 warped exhaust manifold
Post by: erickedwards0119 on May 15, 2016, 08:49:02 PM
Hi, I'm a new owner of a 1987 eagle wagon. Has anyone tried these headers http://www.summitracing.com/parts/hed-99610/overview/ ?  It says they are for CJ7s. It would be awesome if they fit on the eagles. 
Title: Re: 258 warped exhaust manifold
Post by: amcfool1 on May 16, 2016, 10:08:07 AM
hi, no those will not fit, The ONLY eagle header is from Clifford, almost $400. IMO not really worth it unless you have money to burn. good luck, gz
Title: Re: 258 warped exhaust manifold
Post by: mudkicker715 on May 16, 2016, 06:45:42 PM
Not true. With minor mods some kind of manifold for a 7120 head xj works. I did almost nothing to make it work.
Title: Re: 258 warped exhaust manifold
Post by: vangremlin on May 16, 2016, 07:33:35 PM
Yes, I also used the "header" style manifold for the 7120 head and it fit in my Eagle with some persuasion.  There is a picture of the manifold in this thread

http://forums.amceaglesden.com/index.php?topic=42319.0;all
Title: Re: 258 warped exhaust manifold
Post by: amcfool1 on May 16, 2016, 11:33:38 PM
yes, on a 4.0 head, do they work on a stock 258 head? thanks, gz