Can an SR20 block be re-threaded? stripped with banjo bolt

[SketchyRollin564]

To make it short, i swapped my blown turbo two nights ago. Putting the new one in, me and my friend were working on different things at once to get things done and put back together quicker. He was the one who put in the banjo bolt for the oil line that goes to the turbo tward the bottom of the block. Im guessing he put it in crooked or something, because when i started the car, it began leaking oil down there. We figured okay, it needs to be tightened more... well when we went about this, it just kept spinning.

Taking the bolt out we found metal strippings from the block! Awesome! With my luck this would happen... and with the actual block and not the bolt (im guessing cause its an aluminum block and the bolts probably tougher). Another friend had a good idea, and we tried removing all the crush washers to see if we could catch deeper threads, and some how, miraculously, this actually worked and it didnt leak.

I cleaned the area with brake parts cleaner to check for leaks. Didnt leak under idle with cold oil (higher oil pressure), and not under mild reving either. With the car and oil all warmed up and not leaking i did a couple of hard pulls to see if it would leak, and when we got back it was still dry

This is good, since it means i can still drive around and get to work, but this also means that that bolt is only held on by like two or three loops of threads. Meaning it can easyly back out, or break the threads at any given moment... i dont need that to happen



Does anyone have any ideas on what i can do? I was thinking possibly i could re thread it, but i dont know if that will actually work on a block. In the mean time ill be checking that banjo bolt every time i get into the car and ill be ordering a cheap prosport oil pressure gauge asap to keep an eye out on it, but i still want to fix this as soon as possible so i can take my car to the next drift event and not have to worry about this. And so i can drive period without this risk.

any help/ideas/suggestions GREATLY appreciated!



Cliff Notes: Swapped turbo, friend put in banjo bolt for oil line and somehow stripped threads on block. Leaked oil, removed crush washers, now doesnt leak. Problem: Bolt only held on by 2 or 3 loops of threads. Huge risk to drive like this. Solution? no fcking clue... wanna help?

[240sxAli4Life]

Sorry i know this is completly off topic, but what wheels are those up front on your s13???

[SketchyRollin564]

lol the same wheels in the back, just differnet size.

they're some gay rims called "drifz 502". They are weak a** sizes and offsets too, the only reason they almost sit flush is because i have 25mm spacers up front and 15mm spacers in the back. With RUCA's i will probably be flush, or poking a tad in the back. Im not into the whole camber thing, but i have stock rear arms

I only have these wheels cause i traded stock 300zx wheels for them, i plan on using these as drift spares and getting either rota grids or XXR 527's to daily. These wheels have horrible sizing, you do not want them lol. They are 17x7 +45 up front and 17x9+35 in the back. They looked horrid without spacers

[Hoffman5982]

You should be able to rethread it, but my biggest worry is metal shavings getting inside the motor. I'm guessing you are using the factory lines? Rethreading it with the factory thread size might not work as the tap won't catch since you stripped the hole out. The only other thing I can think of is, if you have factory lines, make an AN line and go a step up with the adapter. That may not make any sense but here is what I mean : http://www.summitracing.com/parts/SUM-220648/

Someone with more experience would need to come in and tell you what size you would need, and then you would just buy the appropriate tap and hope for the best. I almost did the same thing when I had the factory lines. It's real easy to do with those things

[Hijacker]

Given that those are pipe threads, I'm not sure if it can be rethreaded. Helicoils aren't pipe threads, but I do believe there have been some successful fixes for the banjo bolt holes reported in the forums.

[terry_240sx]

you could try drilling it out and tapping it for the appropriate helicoil..

[SketchyRollin564]

I posted this on a local forum and it sounds like the helicoil is the way to go. Im actually not using stock lines, i have braided stainless steel lines. Someone said they had the same thing happen to them and a helicoil worked, at it hasnt leaked since, which is good to know

im just wondering if ill be able to fit a drill in there, it looks like the engine might need to come out to do this properly

[Hijacker]

Be sure to use thread sealant when you do helicoil it. That will be added insurance against leaks

[OutToWinPAHC]

Yeah I can see a heli-coil leaking too. However some ARP thread seal for head studs that enter water jackets should do the trick. I would tray that myself.

[OM3GA]

I have seen this happen too many times with aftermarket lines...

[Hijacker]

For those who don't quite understand how pipe threads work, and why it has potential to leak, I'll leave a few links for those wanting to learn.

http://mdmetric.com/tech/thdform3.htm

http://mdmetric.com/pdf/Thdfrm2.pdf

http://mdmetric.com/tech/tict2011.htm

Omega, the reason you see this happen a lot with aftermarket lines is probably minor incongruities between the threads of the line, and the threads of the block. And given the nature of aluminum, the multiple retorques each of those bolts have seen, possible cross threading from the factory lines being a b1tch, and heat cycling since it's all on the exhaust side, I'm not surprised to see some stripped threads.

Thankfully, after doing a bit of research on the OPs problem, the factory banjo bolt appears to be 12x1.25mm. So I don't think it's going to need pipe threads, as a quick search should have turned up something BSPT (I did some research a few months back when installing my oil pressure sender to jury rig up an impressive angled adapter -_-). However, while a helicoil should fix his issue, I would still recommend wrapping the banjo bolt in teflon tape or some other thread sealer just to be on the safe side.

[SketchyRollin564]

Thats awesome to read. I was just about to post to ask if anyone knows where i can find out the thread pitch for that bolt.

I was going to guess m12x1.25 because ive noticfed all of nissans studs are x1.25, and i know my turbo elbow stud was a 10x1.25 and its just a tiny bit smaller

i guessed on point lol

Anyways, a guy in my friends neighborhood has rebuilt a few engines and works on planes and stuff, and he has a few helicoil kits laying around and he has experience doing this stuff. Im stopping by his house tuesday for him to take a look at it

thanks for all the help