Wideband O2 or no? '69 manifold

[tcslc]

Hello. After watching a '69 U20 Roadster sit outside for 14 months a few miles from me, I bought the car in August. The body is not rusty, amazing for Northeast and shows it was stored indoors, but it needs everything else. Everything! I've been reading through the site ever since and have already made some great and very welcoming connections.

My first post is about the exhaust manifold. I had it bead blasted and there is a hairline around the Y and a longer crack down the top middle where it was originally welded together. In addition it has a pinhole in the number 1 and 4 tube section. I'm going to have it all welded up and then ceramic coated. and was thinking about making some lemonade out of this lemon manifold by adding an O2 bung to the area where the pinhole is on the 1-4 tube. The rest of the tube is solid when picking at it, and the bung would certainly add some additional metal and strength down there. So, my question is this: instead of a patch, what do you think of welding an O2 sensor bung over the hole (drilling it out to appropriate size, of course) and installing wideband O2 monitoring to help setup the carbs once it's all together? It wouldn't be at the proper placement in the collector, but I would get a reading off cylinders 1 and 4 that would cover both carbs. Think this is a good way to make some lemonade? Thanks!

IMG_7385.jpg

IMG_7386.jpg

IMG_7387_NEW.jpg

[sfdaugherty]

In order for the wideband to work well, it needs to be positioned correctly. I would recommend reading a wideband manufacturer's instructions before you place it. You need samples from the entire exhaust stream, they like some straight distance to reduce turbulent flow, and need to be clocked correctly. I'm not an expert but I don't think that location will work well. If I had that situation, I would install it in the collector

[greydog]

If it's been repaired at least once and you have another crack/hole, chances are you'll soon develop another.
the widebands are particular about location as mentioned above.
So, it sort of depends on what you are looking for? You can stick the bung in and get some sort of output. It may even be useful (but probably not). Still, it'll plug the hole and the output is fun to watch as it changes.
Chances are, you'll develop a crack or hole elsewhere soon.
A longer term fix would be to buy a header, install a bung and have it coated. Costly but you'll have the sensor in the right place and probably never have to worry about it again.
Dan

[JT68]

Good advice above. Just put a little scab on to patch the hole and put the sensor in the forward exhaust pipe. Prob 75% likelihood of re-fracture within a year or so, so ceramic coat is probably not a great idea.

J

[Nissanman]

I would suggest that the entire exhaust manifold is too thin to re-use/repair and should be replaced either by a better OEM unit or a nice new tubular aftermarket set.
Once you start to weld up that hole you might just watch the pipe burn away before your eyes.
The ideal location for the sensor bung is in the collector area just forward of the tail pipe join.