Pacesetter xj/mj 4.0 headers

[misfitmechanic]

I've got my eye on a pacesetter header for my 4.0 ho powered Comanche. Does anybody have any experience, positive or negative with these? I've read some on the net about clearance issues between the collector y pipe and the front driveshaft/front diff yoke. I can't imagine this not being corrected in current production runs. I also wouldn't be too opposed to modifying them if need be for clearence. Thanks for any info.

 

Earl

[Zebvance]

Page 2 and 3 of my build tread list the issues I had with them. Customer service was terrible, was not impressed by the quality. Go with the ceramic coated, for have it coated your self. paint will flake off after the first 25 miles and start rusting. I haven't heard of anyone else really having the issues I had so maybe you won't run into the problems I did....

 

here is the link:

 

http://comancheclub.com/topic/34531-1988-jeep-comanche-aka-the-penny-sniffer-pic-heavy/page-2

[Paul Bruchal]

I had them for my renix 1990 MJ 4x4, i had no problems at all besides the paint coming off and a little rust showed. Id buy them again and heat wrap the pipes . it changes the sound of exhaust alot. deeper sound

[87Warrior]

I have one installed on the 99 4.0 in my 92. Admittedly I haven't driven the truck yet, but the header did fit just fine. You may have to grind a little on the washers that link the top of the header to the bottom of the intake manifold so they sit flat.

 

Pacesetter ships their headers with a cheap paint coating to prevent rust during shipping. The instructions clearly state the coating is not high temperature rated and needs to be removed, and a proper high temperature exhaust paint applied. Stripping the shipping paint is a piece of cake when using 'Aircraft Stripper'.

[Tanner]

I would not recommend pacesetters, had some real fitment issues with mine, and i was unable to install one of the bolts in the manifold because the tubes were bent way too close to the block.

not worth the money saved

[75sv1]

^{I did have a set on my '88 Comanche. No real problems. Mine was ceramic coated. Some flaking at the edges on the flange. I ran it a few years. Most headers do not have the bung for the EGR system. Since yours is an HO, that is not a problem. Mine was an early set. Possibly made in the USA. When they moved to Mexico, I heard there was quality issues. That was long ago though. For an HO, I might look at others. Any header will rust if not coated or SS. I'd prefer Ceramic coating. It does reduce under hood temps. Wrapping with the heat tape will cause the header to rust. I don't know if ceramic coating would stop that. It should, but then why wrap them is ceramic coated. I'd compare cost. I did like the clamp section vs no clamp section of other headers.}

[neohic]

I've got a ceramic coated header on my Eliminator and I like it. No issues with fit up but I always wanted to get a couple nice band clamps for the Y section. The supplied exhaust clamps sealed up fine, but it seemed like each year I'd have to loosen them to push the Y back together. Last spring I was changing the oil and the welder was sitting just a little too close to the truck... sure was an itch just too deep not to scratch. Couple stitch welds later and I don't need band clamps anymore.

 

Next time I have an excuse to pull it out, I'll add a couple nice unions in there instead... probably.

[misfitmechanic]

I ordered the pacesetters this morning. I found a screaming deal on Amazon that I couldn't pass up, about half the price that I could buy them locally and free shipping. One reason I really like the design of these is that they come with a intermediate pipe that goes from the header to the catalytic converter. My current intermediate pipe is a oem style replacement that's not mandrel bent and fairly small diameter. I think this is probably the biggest restriction in my exhaust system. Once these headers show up I think I'll strip off the original paint and then paint them with some sort of high heat header paint. It would be nice to get them ceramic coated but I think that would be a pain to fit, possibly modify them and then have to takem back off to get them coated but I'll see once I get that far. Thanks for all the replys.

 

Earl

[Bobolink]

You've ordered them already, but in case you haven't installed them yet, here's a couple pointers (mine on a '90 Renix). I found that I burned through the gasket, with or without the hi-temp copper sealant. Properly torqued and retorqued, still would burn through within a year. Pacesetter folks claimed that a regular manifold gasket from, say, Felpro, would not work. But I finally got fed up with Pacesetter's gaskets (after three tries) and switched to a regular Felpro manifold gasket, and haven't had another problem since (been about four years now). Also be sure to tighten the clamps REALLY good. Those slip joints will do just that ... SLIP! Bolted flanges would've been nice......

[Megadan]

I have the ceramic coated header on my Renix.  The only two issues I had with mine were, 1. As stated above, the supplied washers/spacers for the intake and exhaust manifold bolts had to be ground down some for proper fitment.  Nothing extreme, just added time to the install.  2. The Y-pipe/crossover exhaust section (part that goes under the trans) had to be tweaked and clearanced some on mine where it goes past the bellhousing for the transmission.  It was just barely touching the bellhousing at the bottom bolt on the drivers side.  Not really a big deal (small shallow dent made via hammer) but it did crack the coating on that pipe in the process.  Otherise, everything is fine.

I did not use the supplied gasket, but instead opted for a higher quality unit from the parts store that I had on hand since I was replacing the cylinder head.   Lots of other people also recommend not using the supplied gasket, including the post above mine, for the same reason of burning through.

Just do yourself 1 favor and use some tailpipe/exhaust junction sealant.  I had a problem with my Y pipe junctions leaking a bit even with the clamps tightened down, so I used a liberal amount of it on those 2 slip joints and it hasn't leaked since.   FWIW, if you want to spend the money, go get some higher quality exhaust clamps for the Y-pipe junction.  The ones supplied are pretty cheap (crap).

[misfitmechanic]

I still haven't had a chance to install this header yet, just got my truck out of winter storage. The washer supplied with my hardware kit are machined with a step in them and I assume this is to account for different flange thickness of the header/intake. Also I wasn't planning on using the supplied gasket as it was kinked during shipping. I was also thinking of getting a couple flanges laser cut out so I didn't have to use the muffler clamps on the y pipe

 

[Megadan]

The washers do work, but I had to grind a couple down in order to get them installed with the bolts.  Mainly the to bottom center bolts, which I could just barely not get installed thanks to the primary tube being in the way.  Honestly, I think every set of headers has it's own problems with Pacesetter.  Wide degree of manufacturing variances.

BTW, That' one sexy truck!

[misfitmechanic]

Thanks!

[Bobolink]

Yeah, I forgot about those dang washers....I had to do some grinding, too, just to make them the proper thickness on each side. It was usually not ground out deep enough on the thinner portion that clamps the thicker intake manifold, as I recall.