Welding exhaust bung in pipe help.

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my5thmopar

my5thmopar

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I'm going to weld the bung this week and hook up the Innovate AF meter. I can weld but, this is something I've never done. I have a few questions since I'm getting conflicting info from my searches. Thanks

Can someone point me to a how to that works or instruct me how to?
Should i drill the hole ID or OD of the bung?
Do I need to flatten the pipe or grind the bung to match pipe?
 
Doesn't the bung already have a curvature on one side of it? All the one's I've seen do.
 
Not all bungs are created equal,the type I sourced from carquest were not
scalloped on one side,and were stepped on the OD.The step would sit into an appropriately
sized hole,and it's depth would accommodate the pipe curve,simple enuff.The threads are a
little deep, so the sensor doesn't intrude too far into the exh. stream,but that's not the most
critical if it's just for tuning.If the bung is a flush-mount,I drill the pipe the OD of the THREAD
and use an old sparkplug to align it,then weld it in place.That way you're not welding the
heavier bung to the pipe on the edge,and you can flatten-pipe or scallop bung w/o affecting
anything,other than cleaning/chasing the threads if choosing the latter.
The really critical item is placement in the system, particularly if you are doing
duals, to get accurate & balanced readings.
 
Put an 18mm spark plug (Ford straight 6) in the bung when you weld it in, this will give you something to hold on to and keep spatter out of the hole. When drilling the hole make sure it big enough to get the tip of the O2 sensor through but not so big that the bung falls through.
 
I use 18mm nuts as bungs.

Shape the nut to the curve of the pipe.

Sand off/grind the metal clean on the pipe.

Hose-clamp the nut to the pipe, and tack weld.

Remove hose-clamp, complete welds.

Test for leaks by adding water to the bung hole.

When there isn't any leaks, I drill out the hole in the pipe.
 
emsvitil said:
I use 18mm nuts as bungs.

Shape the nut to the curve of the pipe.

Sand off/grind the metal clean on the pipe.

Hose-clamp the nut to the pipe, and tack weld.

Remove hose-clamp, complete welds.

Test for leaks by adding water to the bung hole.

When there isn't any leaks, I drill out the hole in the pipe.
Click to expand...

I think they make a special rubber bag tool for that. :D
 
Also mount the bung so that the sensor is at least at a 10 degree angle. This is so condensation doesn't sit on and ruin the sensor.
 
^Yup, drill a 3/4" hole, weld it with a 18MM oil pan plug bolt installed so you don't have to tap, also don't bother welding the header, weld the reducer adapter so you can install/remove it easy.

Welcome to the dark side!
 
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