I need a really large drill bit!

[Nitrousbird]

The biggest thing holding me back from making progress on my car is the headers. I need to get the O2 sensor fittings welded into my headers. But I don't have a drill bit big enough to make the hole big enough.

 

I need a drill bit that would be approx 23mm. The threads are 18mm, plus adding to the thickness around the fitting, it would be about that. I mean, if it is close and I just have to grind a bit, that's fine.....but I need something close.

 

Anyone have a bit like this?? Once I can get the fittings in there, I can take them anywhere to get welded; it's a 2 minute job for that part.

[BiG BeN]

i have one...it's a step bit.goes to 1.5" costs about 75$ from graybar

[Renner]

Why are you drilling the hole that large? Your best bet is to drill the hole ~16mm, and then center the fitting over the hole flush on the outer surface of the pipe so that it does not hang into the exhaust flow. Then weld around the circumference of the fitting. Lastly, use the 18mm tap to clean up the threads on the now slightly warped fitting, and to finish tapping the threads through the 16mm hole you just drilled in the pipe. This will leave a nice flush surface on the inside wall of the pipe and you will have clean threads all the way through. It will come out looking like this (if you can see it): http://images.cardomain.com/member_images/4/web/160000-160999/160293_203_full.jpg

[Nitrousbird]

Brett, I suppose I could do it that way. I figured since all of the other headers I see w/ O2 bungees welded in have them welded INTO the header, I would do the same. But that would work as well, so maybe I'll just open up the hole I have enough for that. smile.gif

 

Hell, how much would you charge to weld it on for me (they are out of the car, I'd just have to bring them to you)?? I've never welded before, and I'm not about to start experimenting on a $550 set of headers.