18mm Bung Length

[Ohio HD]

Guys, I'm finding 18mm weld in O2 bungs on line that are 1/2" long, and 3/4" long. What length works best with the HD 18mm O2 sensors?

I'm not to lazy to pull one out and measure it, but I'm on the road working till Friday, and want to get them ordered before then.

Thanks

[wurk_truk]

Brian.  I would get a pair of each.

[Ohio HD]

Yep, better safe than sorry.

[Steve Cole]

Guys, I'm finding 18mm weld in O2 bungs on line that are 1/2" long, and 3/4" long. What length works best with the HD 18mm O2 sensors?

I'm not to lazy to pull one out and measure it, but I'm on the road working till Friday, and want to get them ordered before then.

Thanks

Do not bother getting the 3/4" long ones as the Bosch specification calls out for 5/16" so even you 1/2" long ones would need a little trimming

[Ohio HD]

Thanks Steve, I have two types of 1/2" coming. I'll trim to what ever needs to be done. Do you gave a link by any chance that describes, or shows, examples of preferable fit of the sensor?



Brian

[Steve Cole]

http://harleytechtalk.com/htt/index.php/topic,44573.0.html

You should find most of what you need in there. There is no perfect solution that works in all applications but we recommend you follow the BOSCH specifications, as we have found those to work best.

[Ohio HD]

http://harleytechtalk.com/htt/index.php/topic,44573.0.html

You should find most of what you need in there. There is no perfect solution that works in all applications but we recommend you follow the BOSCH specifications, as we have found those to work best.

Looks like a lot of info there, I'll definitely go through this before I attempt to add the additional bungs. I figure I'll just plug the originals, rather than cut them out and weld a patch.

[HogBag]

Ohio HD
The best way to mount the 18mm bungs is between 4 to 6 inches from the exhaust port and on the long radius of the bend on the header. The Bosch specs call for the bungs to be on a angle to stop condensation fowling and collecting inside the sensor. Mount your headers on the bike and try and see where the low RPM exhaust gases would flow to keep the sensors heated and sampling with the Bosch angle and depth if possible.

[Ohio HD]

http://harleytechtalk.com/htt/index.php/topic,44573.0.html

You should find most of what you need in there. There is no perfect solution that works in all applications but we recommend you follow the BOSCH specifications, as we have found those to work best.

Ok, so I had some time last night to go through the link you posted for me. And there was a link that Jason had posted about trimming existing bungs down, http://harleytechtalk.com/htt/index.php/topic,38168.0.html , nice pictures and procedure by the way Jason.

And I also did s search on the HTT site and found the web link to the Bosch catalog, that speaks to O2 placement. So here's what I'm going to look at when I get home from Tennessee today. I think that those D&D pipes may have the O2 sensor out of the pipe and exhaust stream pretty far. So I'm going to look at that close, measure the depth by a wire, then look at the sensor. If it's out by much, I may just try to trim the bungs down to get the sensor into the stream, and then see how things are with a V-Tune, and does it change the VE's now. If it doesn't help, then I guess relocation is needed.

I suspect that if they're out of the stream much, that this may be the entire problem. I was always able to get a pretty clean VE from tuning, meaning the tables would go from Red, Pink, Then to White. But maybe because I had performed a lot of tunes to get the data clean. We'll see I guess.

As always, a lot of good info and help from this site.