But....but....3/4 is the same as 6/8, and that's bigger than 5/8. Won't it just fall through?

 

I went through the same thing your going through now trust me I did the same calculations but remember your getting a TAPERED pipe thread tap so it starts at 5/8 and then tapers up bigger from there it works I promise I would not steer your wrong

 

This what my mechanic is going to do, he is going to weld an aluminum nut on the oil pan will drilling of course, and he will make sure I can thread my oil return barb through the new hole, so lets say turbo goes bad ok go back to N/A just screw in a nut to cover the hole its a win win situration

 

I think what's confusing me then, is where everything is measured. The drill bit is 3/4" in diameter, ya? And the tap is 5/8" diameter at the tip? but gets bigger? I googled a chart of "drill bit size for tap" applications, and they are all saying the drill bit is slightly smaller, so that the metal sort of bents in as you tap. I think that I'm not understanding what is actually what size. Did you take a pic of the tap and drill bit you used? also, does the tap have what size drill bit to use written on it? I only have 1 tap, cause I needed it for a "helicoil" i put in the buick once. It's a 12mm tap, and the drill bit number says 10.9 on the side, is that the same as what I'm asking about here? I hate it when something so dang simple confuses me, lol.

 

+1 on this, I'm doing it! excellent idea. I hadn't even thought about it, but I've got a welder buddy so he should be fine doin this.

 

yeah lol, I was like I need you to either weld this barb in or drill a hole, and he was like bro thats aluminum you cant weld those metals together so he was thinking and he was like lets just weld a nut on there to screw on and I thought about it for second figuring out how this would work and I didnt see any problems with it so thats what im doing besides welding a barb or tapping the oil pan, because thats the most important part

 

Looks like it's different to weld aluminum....maybe I'll just do the tap and jbweld it inplace.

My buddy doesn't know how to weld aluminum, lol, just exhaust pipe.

 

THe 12mm you speak of it probably a standard not tapered tap. I heavent looked at the tap set in awhile so couldnt tell ya if it says the drill size. If you do go for the tap get the step drill bit otherwise you will pay a pretty penny more for just a 3/4 bit I know I looked lol

 

who in hell uses pliers to remove an O2 sensor? lol. awesome.

 

P.S. you can get brass bulkhead fittings for your oil pan. you drill the hole, then feed the male, -an threaded part in and a nut screws on from the inside. they even come with o-rings for a nice seal.

i did this on my old honda. worked flawlessly.

here are examples of female and male-ended fittings:

 

Welding is the way to go.. the aluminum is very contaminated, so the weld might not be pretty.. but its 10x better then having to deal with tapping and dealing with any leaks you might have.. bulk head fittings have proven time and time again to leak just as bad as tapped oil lines..
it might cost a little more if u dont know someone who can weld alluminum for you.. but u can get Uncoated Aluminum fittings that are ready to weld from Jegs for very cheap. then u can just use any adapter you want on it for your oil line..
and if u ever go back to NA and dont need the connection, u can get a plug for whatever adapter you welded to the pan.

welding is always the best option.. but if all u care about is Ghetto buildin your stuff, you will have to keep up with fixxing and monitoring it 24/7.


1 aluminum fitting + a welder.. or... 2-3 brass fittings, buying some tools u probably dont have, and more locations to leak from.. weldin it might cost a little more.. but 10x less headaches

 

To be fair, I never had a bulkhead leak, ghetto though it may be. After that, we began to weld them to the pan from the inside. Yay for steel oil pans.