DirtyComanche Posted April 14, 2016 Share Posted April 14, 2016 Actually an XJ thing, but it's the same for what matters in this case. 89, Renix, 4.0L Factory exhaust is scabbed, broken, doesn't fit right, has a 'newer' catback on it that's totally rotten because it was bare steel. Anyways, Renix parts are always harder to come by, and seem to be a premium. So I was thinking I'd massage the intake and install this header: http://www.amazon.com/Wrangler-Cherokee-Performance-Stainless-Polished/dp/B00JA1BGYY?ie=UTF8&psc=1&redirect=true&ref_=ox_sc_act_title_1&smid=A1F86TF7G43XA2 Any experience with it? Reading the reviews on Amazon is mixed. The flange thickness issue is well, an issue, but it can be dealt with by making some custom washers. Obviously there also isn't a bung for my O2 sensor, but on to that... Who makes a stainless downpipe, or 'front pipe' as it seems to be called by exhaust manufacturers, that will fit an HO and have the bung in it? Failing that, does anyone know what flange style can be bolted to an HO header? These maybe? http://www.summitracing.com/int/parts/vpe-1471/overview/(they sell individually also) Is there a flare piece on Summit that will fit the needed donut gasket? Closest I think I can find is for 2.5" pipe: http://www.summitracing.com/int/parts/vpe-2599/overview/ If I have to use that (if it would fit on the header and seal) I would neck it down to 2.25" right away. I do not have any issues with front driveshaft clearance but will have trouble fitting larger pipe from there back. Unfortunately 2.25" parts seem to be much rarer than 2.5". I can buy some U-bends and make the exhaust from the header back if I know what flange and flare will bolt up. Otherwise I'm at a bit of a loss. Buying a weld in bung for the O2 isn't a big deal. I can get everything from there back easily enough if I just buy normal universal parts. Yes, I can weld stainless well enough. Link to comment Share on other sites More sharing options...
Eagle Posted April 14, 2016 Share Posted April 14, 2016 Both the Renix and HO 4.0L engines in the XJ and the MJ use a 2-1/2" down pipe. The catalytic converters are 2-1/2" all the way through, and the converter tailpipe necks down from 2-1/2" to 2-1/4" between the cat body and the muffler inlet. Link to comment Share on other sites More sharing options...
DirtyComanche Posted April 14, 2016 Author Share Posted April 14, 2016 Oh? Well that makes it easier. There's not many parts of the stock exhaust pipe that haven't been massaged to fit it seems, so I always ASSumed it was 2.25". Link to comment Share on other sites More sharing options...
Megadan Posted April 14, 2016 Share Posted April 14, 2016 Weld on a stainless O2 bung on that header. They are pretty cheap and easy to find and would solve that issue. Link to comment Share on other sites More sharing options...
DirtyComanche Posted April 14, 2016 Author Share Posted April 14, 2016 Weld on a stainless O2 bung on that header. They are pretty cheap and easy to find and would solve that issue. Yeah, that was my plan if I didn't get an actual HO downpipe. Summit has them. Cheap, easy. Any ideas if that flange from Summit for 2.5" pipe will fit??? Link to comment Share on other sites More sharing options...
Megadan Posted April 14, 2016 Share Posted April 14, 2016 No idea. I don't have a factory manifold or pipe or I would go measure the bolt spacing for you. Link to comment Share on other sites More sharing options...
HOrnbrod Posted April 15, 2016 Share Posted April 15, 2016 Don't forget a flex joint on the downpipe if possible to help your new header from cracking. Link to comment Share on other sites More sharing options...
DirtyComanche Posted April 15, 2016 Author Share Posted April 15, 2016 Don't forget a flex joint on the downpipe if possible to help your new header from cracking. Yeah, I'm not sure what I'm going to do actually... I had a flex joint somewhere around where yours is the last time I built one of these, worked well, but this is all getting weird on me. Either I'm going to abandon this (and scab what was there back together) because the potential cost is getting out of hand, or I will go all in. I'm thinking I might cut the existing flange off the header and weld a V-band flange on it. Why? Because I know it will seal then, and I know it will fit. From there just buy a couple U bends and a flex joint and start building it. This will be really time consuming. It will be costly too. That 'cheap' header is still $250 by the time it gets to me. Figure another $100 for the V-band setup. Then about $80 for bends. Another $100 for pipe (sourced locally I hope). Then I can either drop $400 for a pre-made catback and hope it fits, or buy more bends and a muffler... Hmm. Link to comment Share on other sites More sharing options...
cruiser54 Posted April 15, 2016 Share Posted April 15, 2016 The wrangler header will probably not fit. Get one for a 91 to 99? XJ instead. Link to comment Share on other sites More sharing options...
DirtyComanche Posted April 15, 2016 Author Share Posted April 15, 2016 The wrangler header will probably not fit. Get one for a 91 to 99? XJ instead. The one I linked originally is listed for TJ/YJ/ZJ/XJ of the HO type, but who knows what it will actually fit. I do not have driveshaft clearance issues with the exhaust (pinion is about 5" farther to the driver's side due to the axle that's in it). I don't know what else would be an issue, the firewall? Link to comment Share on other sites More sharing options...
ScottJeep Posted April 15, 2016 Share Posted April 15, 2016 There are several nice Clamp-On O2 bungs...even SS. Just watched the latest Engine Masters on MotorTrend on-demand and they used one. Went back and looked. They show it but do not say the manufact. And I know what some would say. "We don't use any clamps...welded front to back". Good for you. So you have a tig in your garage for SS huh? Double lucky. Well unless you have the flex pieces Don showed your gonna break something soon. Link to comment Share on other sites More sharing options...
Megadan Posted April 15, 2016 Share Posted April 15, 2016 Good for you. So you have a tig in your garage for SS huh? Double lucky. I have a MIG with 312L wire and a full bottle of pure Argon. Always been more then enough to weld in a bung or two. :D I've heard mixed things about the clamp on stype, but they do work. I wouldn't shy from trying one out if I didn't have a welder setup for stainless and aluminum (spool gun) already. Link to comment Share on other sites More sharing options...
DirtyComanche Posted April 15, 2016 Author Share Posted April 15, 2016 Welding SS exhaust isn't rocket science. No TIG here. Last one I did I used my stick welder, actually. :rotf: I honestly don't care how it looks, I just care that it doesn't rust. I hate rust. Real bad. If I ever built a Jeep Jeep I would just phone Aqualu for the entire body. Luckily (maybe?) I'm not terribly into normal Jeeps. I called the local parts house for some SS flex hose, and they've got 10' set aside for me. I'm going to order some other parts, but that will be a backup if things aren't going to work out. I do not believe in any style of clamp joint other than V-bands or donuts. I would not use a clamp on O2 bung. I might do suspect work, and it might take me a long time, but it's always welded together in a manner that won't come apart. Link to comment Share on other sites More sharing options...
DirtyComanche Posted April 15, 2016 Author Share Posted April 15, 2016 Renix O2 sensors are 18mmx1.5 thread? Link to comment Share on other sites More sharing options...
Megadan Posted April 15, 2016 Share Posted April 15, 2016 Yea, it should be. Link to comment Share on other sites More sharing options...
DirtyComanche Posted April 15, 2016 Author Share Posted April 15, 2016 Looks like I'm sitting at $1200 CAD to do this. Nothing stainless is cheap. Yeah, I dunno. Doesn't make a lot of sense for a street driven wheeler. Link to comment Share on other sites More sharing options...
gogmorgo Posted April 16, 2016 Share Posted April 16, 2016 10' of flex hose? Seems like a bit much... I can understand that costing quite a bit. Link to comment Share on other sites More sharing options...
DirtyComanche Posted April 16, 2016 Author Share Posted April 16, 2016 10' of flex hose? Seems like a bit much... I can understand that costing quite a bit. Yes. Quoted $240, I will pay less. Comes in 10' lengths. It's a backup solution. Basically it's the same stuff used to do big truck and equipment exhaust. If all else fails I will buy it and use it to do from the header to the muffler and have a bunch left over for something else. Do I want to do that? Nope. Would it work? Yup. I threw a Vibrant SS flex coupling in my cart, by the time it gets to me it's still $80. The cheaper Summit ones are NOT actually stainless pipe, just the flex part is. I suppose a guy could cut the pipe off them and just use the flex part to save money? :dunno: 10' of stainless exhaust pipe from the local exhaust shop is quoted at $300. :rotf: Parts store was a lot cheaper, still ugly. It's honestly cheaper for me to just buy the flex hose than it is to buy bends, a flex piece, and pipe to build it the more conventional (and right) way. Link to comment Share on other sites More sharing options...
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