[Cobra Lust]

Topic says it all. I've heard that the sensors should go into 1 and 2 or 4 and 8. Someone tell me where they should go and whether they should go on the top or on the bottom of the pipe.

I had them all bolted up and realized that I hadn't installed the taps so I'll be taking them off tomorrow. I used the gaskets that came with them. Some say to use aluminum gaskets because they won't leak. Is that true, and if so, what kind do you recommend and where can I get them? Another question, can the taps for the sensors be bought some place?

 

[Richard Calhoun]

This topic has been discussed many times, and you will get a different opinion from many people. Many builders put the bung in the first common area in the side pipe. That's what I did. That way you get a reading from all 4 cylinders. Many say this is too far from the head and the sensor doesn't get hot enought. I used Earl's graphite gaskets and apparently they last a long time and they do not leak. But they are expensive. Summit has them and I'm guessing they are about $35????? You also might consider the grade 8 header bolts with locks on them. I have heard complaints that the regular bolts loosen often. Again they are expensive. Maybe $45????? Lastly, I got the bungs from FFR.

Hope this helps
Dick

 

[Wade Chamberlain]

I had my 02's in the collector area, just after the 4 pipes come together, and they would never get hot enough to stay in closed loop. I moved them to one primary on each side and it works fine. Pick whichever pipes you want, and mount the 02's about 12-14" away from the head. I don't remember which pipes I used. I just picked the one on each side that was easiest to weld a fitting into while the pipes were still on the car. I mounted mine on the bottom, so they are totally hidden from view.

EDIT - I forgot to mention the gaskets/bolts. In my opinion, the Earl's gaskets and Stage8 header bolts are the only way to go. "Regular" header gaskets lasted less than 2 hours on my early FFR 4x4 headers. Earl's have been leak free for 22,000 miles. Also, the FFR header flanges are really thick. Combined w/ the extra thick Earls gaskets, you should get the 1" long bolts rather than the standard 3/4". Same part number, but with a "A" suffix.

[ December 29, 2002, 07:46 AM: Message edited by: Wade Chamberlain ]

 

[Stu Spencer]

Wade,

I thought that the O2 sensors are 3 wire and therefor heated and should run closed loop. Also, aren't they near the cats on the Mustang (under your tucas) which is more than a foot or so away. I'm wondering if anyone else has had to move theirs also.... Curious minds want to know

 

[Bart Carter]

Early sensors were not heated and needed to be mounted within 10 inches or so to stay hot enough.

That is the reason heated sensors were developed.

 

[Wade Chamberlain]

Stu - they are 3-wire, and the heaters will "help" them come up to operating temp quicker. However, I'm not sure if the heaters can get them hot enough to stay closed loop. Maybe somebody w/ more intimate knowledge of 02 sensor operation will chime in. I know a lot of mustangers w/ long tube headers have the same problem.

The stock 02's are just a few inches downstream of where the pipes bolt to the header flange, so they're not very far from the head at all.

 

[KobraKurt]

Let's try and get a good answer to this one - I've still got to drill and weld O2 bungs on mine.

Also, where do I get the Earl's gaskets (SUMMIT?!?!) And do you have a part number?

 

[KobraKurt]

DUUUUUUHHHHHH. Helps to read all the posts. SUMMIT it is. Still could use a part number.

 

[Wade Chamberlain]

http://store.summitracing.com/partdetail.asp?part=9841

 

[Cobra Lust]

I called Mike Forte today and he has everything I needed. I got the 1" long Stage 8 header bolts, the Earl's gaskets and the O2 sensor bungs. Mike is a sponsor of this forum.

 

[KobraKurt]

Wade,

So you mounted your O2 sensors on one cylinder about 12" from the heads. Apparantly they get hot enough to maintain a closed loop. Are you concerned about, and isn't it possible to get lower performance from, or to hurt other pistons and cylinders as a result?

 

[Wade Chamberlain]

Kurt - yup, that's the risk you run. If everything is in good shape, you should get the same 02 reading off all cylinders. However, you could conceivably clog an injector and never know about it until you melted a piston! I have an air-fuel ratio gage in the cockpit and can select (by switch) which bank it's reading. I flip back and forth every once and a while to make sure that both sides are reading similarly. Other than that, I run good fuel and the occasional can of fuel injector cleaner to try to minimize the chances of a clogged injector.