[Eric Ruhl]

Looking for some suggestions on how / where to mount this thing. I have a 401 with the stock manifolds and the air injection smog crap. I'm installing TBI off a GM 454 and need to install the O2 sensor. Ideally I'd just tap the manifold and screw it in, but the walls are too thin. I'm tempted to pick up a piece of scrap cast steel and weld it to the manifold as a boss and tap that, but thought I'd look for other ideas first. I prefer mounting it in the manifold because it eliminates a possible exhaust leak before the sensor (the gasket between the pipe and the manifold... that sucker always seems to leak for me <IMG SRC="smilies/rolleyes.gif" border="0"> ). I see a couple alternatives, one being just welding a nut to the pipe and installing the sensor there (which brings into play that possible leak), or ditching the cast manifolds and buying headers and welding the nut on the header (do any AMC V-8 headers come with O2 sensor mounts?). Waddaya think, how/where would you (or have you) mounted an O2 sensor?

 

[CJ5-Man]

first, if you dont like leaks, dont do headers.

I'd just weld a bung into the exhaust pipe right below the manifolds. if it leaks, replace the donut gasket.

 

[mike]

Jeep puts it right after the collectors on the 5.2... That's where Id put it.

 

[Eric Ruhl]

Mike, do they put it in the manifold or in the pipe?

Also, do you guys think I'll need to ditch the air injection? Won't that screw up the O2 reading? I don't see how it couldn't screw it up <IMG SRC="smilies/confused.gif" border="0"> Plenty of these manifolds in the boneyards, I'm thinkin' it wouldn't hurt to pick up a pair and at least give my boss idea a try. <IMG SRC="smilies/beer.gif" border="0">

Thanks for the suggestion Flem. I think it's the actual clamp that is the problem. It's tweaked from being over-tightened over the past 25 years. I plan on replacing the studs if I can get them out. Every time I go to remove those nuts I cringe and wait for that "snap" <IMG SRC="smilies/biggrin.gif" border="0"> I need to get those clamps off the pipes and find some new ones at an exhaust shop if I can.

 

[mike]

It's in the pipe. Just in front of the cat.

 

[CJ5-Man]

Good luck finding those clamps, when I went from headers to manifolds I had to get them at a junkyard. No parts places, exhaust shops, or dealerships had them.

 

[Zombie]

I got the Holley TBI installed on my 304 with headers. I installed 2 O2 sensors, one on each collector. Have had no leaks at all. Drilled the hole, mig welded the bungs and inserted the O2 sensors.

 

[ozarkjeep]

is there not anywhere in teh stock manifold thats thick enough ( how about the already threaded air ports?) maybe they are too far up stream..

good luck welding another piece of steel on top, the amc factory manifolds are VERY dirt cast material.

Ill face this same problem in the future, so Ill listen to solutions offered

 

[CSP]

My Howell instructions say to install the O2 sensor approx 3" downstream of the manifold to pipe flange. They also say to remove the air pump system.

 

[Eric Ruhl]

Originally posted by The Flem:
<STRONG>Good luck finding those clamps, when I went from headers to manifolds I had to get them at a junkyard. No parts places, exhaust shops, or dealerships had them.</STRONG>

Crap, that bites. Maybe I can straighten mine and reinforce them somehow. If not then I guess I'll be looking for better ones in the boneyard as you did <IMG SRC="smilies/frown.gif" border="0">

Ozarkjeep, I hoped there would be a place thick enough to drill/tap the manifold but alas no <IMG SRC="smilies/frown.gif" border="0"> Those air injection ports would be WAY too far upstream. I agree, welding on that manifold will be a serious biotch.

Anybody know if any of the AMC V-8's came without the air injection? If I remove it I'll have to plug the holes in the manifold, but it'd be nice if there are manifolds available without those holes.

At this point I guess I'll suck it up, mount the sensor in the pipe, and be sure to fix that blasted leak at the manifold/pipe joint. Thanks for the suggestions!!

 

[ozarkjeep]

Im pretty sure the older manifolds dont have the air ports, but they may be so old as not to have the dogleg ports too, Im not sure.

there are bolts available in teh correct dimension on teh ports, I ground mine flush then had them thermal barrier coated, you cant even see them now.

 

[NE-RokToy]

Originally posted by Eric Ruhl:
<STRONG>Anybody know if any of the AMC V-8's came without the air injection? If I remove it I'll have to plug the holes in the manifold, but it'd be nice if there are manifolds available without those holes.

At this point I guess I'll suck it up, mount the sensor in the pipe, and be sure to fix that blasted leak at the manifold/pipe joint. Thanks for the suggestions!!</STRONG>

What do you need as far as manifolds my freind has a J-20 that he is getting rid of and it has 360 and I'm pretty sure no airpump. What do your manifolds look like I can lokk at them and tell you if his would work for you.

Oh yeah I don't see why mounting the 02 sensor in the pipe will be a problem, this will give the best sampling and compromise for all cylinders