I am installing side pipes on my 81 vette. I want to retain the comuter controlled carb/distributor. For that, I need the oxygen sensor. I am having trouble finding a bung to weld into the new exhaust pipe to re-use the existing sensor I have. I only have one mounted on the left exhaust pipe just under manifold dump.

Does anyone know where I can get the bung I need ?

Seems like they should be common place. Maybe I'm not looking in the right place.

 

You can get them from a good auto parts store, order from Jegs, Summit, Jags that Run, Street and Performance...

You can also make your own from cheap spark plug anti-foulers.

 

markdtn,
Thanks. I went online to summit parts, found a whole bunch. Another piece of the puzzle solved.

 

Keep in mind of you mount the sensor any farther away from the exhaust port than original you may need to go to a heated sensor for it to work right

 

You only need one.

 

Thanks for the tip.
I am changing from the stock tubular style shorty header found on the 81 to cast iron rams horn I am getting from another member. The rams horn flows a lot better but dump out at the same place, so I should have no problem putting in the exact same spot. A couple inches below the dump out.

 

I thought I read a thread one time that someone had one on each side?
Could be wrong.
Dont know why you would though, one makes sense.
Thanks!

 

I got mine welded in at a Midas shop. They had the bung and in stock. You can also get them at NAPA and do your own welding.

 

Wasn't me but I do have two. First, I wasn't sure about the best way to wire the O2 as to which side and I also want to be able to use an A/F meter on occasion and need a second port.

 

81 only requires 1 for the CCC. But as long as your doing this I would put a bung on both sides and just plug the passenger side. Nice to have the port for an A/F meter should one appear in your future

 

If you don't mind me asking, where did you find the info that the Rams horns flow better than the tubular style headers used on some 80, and all 81-82 Vette's? The info I have read states that the stainless tubular style headers flow better and weigh significantly less, which is why the were adopted during those low power years--to preserve as much hp as possible.

Thanks,
Craig

 

What's the going price for the bung and cap?

 

That's exactly why I put a bung on each side...

About $6...

 

Not trying to hijack but I was wondering what the most effective location for the bung would be. The sidepipes seem to limit your choices here (hard to believe with all those chrome tubes snaking around!). Most people say to mount the O2 sensor on top of the pipe, near the collector, but in no cases should it be mounted below the 90 degree point - directly to the side of the pipe - or condensation will destroy the device too quickly. If you follow this guidance, you'd have an O2 sensor sticking out the top of your collector in plain site from the outside of the car. Not an aestheticly pleasing feature. Others use the O2 for tuning and say to put it within 6-10 inches of the head on the leanest running cylinder. Jet for the lean cylinder to keep your motor on the conserative side of the lean/rich curve.
Has anyone found an acceptable compromise for this header/sidepipe O2 location? Maybe it could be mounted on the collector but tucked/angled to keep it safe, out of site, and functional for a reasonable lifespan?

 

[QUOTE=CRAIGVETTE;1563655555]If you don't mind me asking, where did you find the info that the Rams horns flow better than the tubular style headers used on some 80, and all 81-82 Vette's? The info I have read states that the stainless tubular style headers flow better and weigh significantly less, which is why the were adopted during those low power years--to preserve as much hp as possible.

Hi Craig,
If you have any info to pass along, I would like to review it re these two types of manifolds. I heard the shorty headers dont flow well. I wouldnt mind any info you may have or be willing to share. I would keep the ones I have if I knew different.

But Brezezinski, which is a company that specializes in racing w stock exhaust manifolds, says the rams horn are the best flowing. The 2.5" are even better than the 2" and then they have a ported version that is even better than that. The case that they make is that because all cylinders dump into one common place, scavenging of exhaust gases in more usefull than each cylinder having its own seperate pipe. In the rams horn, the momentum from one cylinders exhaust flowing out can help pull another, thus moving the gasses more quickly.

Thats what I know for what its worth.

 

Frank,

Shorty headers do not flow as well as long tube headers, but they still flow better than stock manifolds. I will try to find the book where they talk about the 80-82 tubular header type manifolds and forward that info on to you. Stock Corvette SBC manifolds are only 2" rams horns, but I am sure that ported 2.5" rams horns manifolds would flow better than your stockers and as others have mentioned, you can still buy those new.

Craig

 

Thanks Z-Man, I assume that's from Napa?

 

Frank, as I mentioned earlier, shorty headers flow better than stock rams horns type manifolds. That is why the C5 and C6 use a shorty header type exhaust manifolds. Shorty's certainly do not flow as well as longtube headers however, which is why you often see them replaced with longtubes. According to both Corvette 1968-1982 by Mike Mueller, and Corvette C3 Buyer's Guide 1968-1982 by Richard Prince, the stainless steel tubular shorty header manifolds were first introduced on 1980 California models, that due to emissions could only get the 305ci engine instead of the 350. By using the stainless steel tubular headers, they not only saved weight, but also managed to get the 305ci California engine to put out just 10hp shy of the 350ci engine for the other 49 states. Because of this performance and weight savings, the tubular stainless steel shorty headers were then put on all 1981 and 1982 Corvettes which increased their output as well. So if you have the stainless tubular headers, they are certainly going to flow better than the 2" rams horns, and still probably as good if not better than 2.5" rams horns, and they certainly weigh less. Hope this helps and good luck.

Craig

 

Just about everywhere - I think Autozone and Checkers have them also. Now that I think about it, the local muffler shop had them too.

 

[QUOTE=CRAIGVETTE;1563676032]Frank, as I mentioned earlier, shorty headers flow better than stock rams horns type manifolds. That is why the C5 and C6 use a shorty header type exhaust manifolds. Shorty's certainly do not flow as well as longtube headers however, which is why you often see them replaced with longtubes.

Hey Craig,
Thanks for the info and your time. That is interesting. I am installing the factory side pipes on this 81 which have 2" exhaust pipes leading down to the side pipe mufflers. Sounds like I should just keep the shorty's on there as long as the factory sides bolt up to them. I know they bolt right up to the rams horn. I would think they both dump out at the same point w respect to the car. At least they appear to without having them side by side. Hey, you learn something everyday.
happy motoring!